Consultative Group on International Agricultural

Consultative Group on International Agricultural Resetich
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From:
April
28,
MT/94/07
The Secretariat
Mid-Term
Soil,
Water,
Meetina, Mav 23-27,
New Delhi,
India
and Nutrient
Manaaement
1994
1994
Research,
A New Auenda
At International
Centers Week 1993, the Group asked the CGIAR Task
Force for Agenda 21 to take a special
note of the study then in progress
under
the auspices of IBSRAM, when preparing
its proposals
for developing
marginal
lands.
That study has since been completed and its findings
are contained
in
the attached
report.
this
report
Members of the Group will
be able to discuss the recommendations
in conjunction.with
those of the Agenda 21 Task Force.
Attachment
Distribution
CGIAR Members
Center Board Chairs
Center Directors
TAC Chair
TAC Members
TX! Secretariat
of
IBSRAM Position Paper
SOIL, WATER, AND NUTRIENT MANAGEMENT
RESEARCH - A NEW AGENDA
DENNIS J. GREENLAND - United Kingdom
GLYNN BOWEN - Australia
HARI ESWAMN - USA
ROBERT RHOADES - USA
CHRISTIAN \yALENTIN - France
Preparedunderthe auspicesof
The Australian Ccnlre for International Agricultural Rescxch
The French Ministry of Foreign Affairs
The OverseasDcvelopmcnt Agency, United Kiugdoul
The Swiss Developnxn~ Coopcmtiou
The U.S. Agency [or Intcmalionn! Developnlcnt
CONTENTS
Page
Foreword
Preface
Goal statementand terms of reference
Executive summary
I
II
III
IV
V
Annex
Annex
Annex
Annex
Annex
Annex
Annes
Annex
SWNM and the challengeof sustainability
An integrated approachto SWNM
SWNM research:the new dimension
Researchpriorities
Harmonizing activities - and a suggestion for implementation
I
II
III
IV
V
VI
VII
VIII
of unsustainability
The symptoms
The farmer-back-to-farmer approach
BiophysicaI problems of SWNM research
Characteristics of the target zones
SWNM problems of the target zones
Responsesto the questionnaire
Comparative advantagesin basic, strategic, applied, and adaptive research
About the authors
Bibliography
Acronyms and abbreviations
1
3
4
.‘.
6
12
21
32
37
43
47
48
52
54
58
60
62
63
71
Foreword
Agriculturalists have long recognized human dependenceon the conservation and
managementof soil, water, and nutrients. In our time, this concern is being felt more and
more by the entire human community. For example, the price of soil erosion is felt more
by the downstream water users than by the farmers from whose fields the soil came. All
humanity suffers when water is poorly managed or inefficiently used. Likewise, the
managementof plant nutrients affects not only food productivity, but the quality of our
water resources.
The growing universal concern for these natural resources is seen“‘in the
international fora concernedwith environment and sustainabledevelopment. In Agenda 21
of the 1992 UN Conference on Environment and Development (UNCED), problems
arising from the mismanagementof soil, water, and nutrients were recognized. Likewise,
earlier international conventions referred directly or indirectly to the need for better
managementof these resources. The process of desertification that received so much
attention in the 1970s and 1980s is basically a soil and water problem. Similarly, at
international global-warming conventions it was noted that soil, water, and nutrient
managementgreatly affect and will be affected by the climate change process. Likewise,
the managementof these three resourceshas a profound influence on biodiversity belowand aboveground.
The wise managementof soil, water, and nutrients is critical in sustainablefood
production. Such managementtruly provides a “win-win” scenario for increased food
production and simultaneous environmental quality enhancement. Unfortunately,
however, the long-range benefits are sometimes not immediately obvious to today’s
farmers or businesspersons. As a result, some science-createdand -tested technologies
that increase yields and simultaneously conserve soil, water, and nutrients are not being
used on farmers’ fields. There is all too little motivational research to identify what needs
to be done to stimulate farmers to use improved technologies and systems more
effectively.
Another constraint on soil and water managementresearch is the fragmentation of
the efforts, along with the lack of a rational system,of sharing researchinformation. Little
attention has been given to the identification of researchpriorities and the development of
strategiesto carry out the scientific investigations. While additional financial support will
be needed for this type of research, much can be done to better plan and coordinate the
work that is already under way.
This report helps us understandmore clearly the nature of soil, water, and nutrient
management problems. It also identifies some areas of high priority and suggests
mechanismsfor better planning and information-sharing. It also shows how such research
can be integrated with research concerned with genetic improvement and systems
management,
IBSRAM and the authors of this paper should be congratulated on taking this
important first step. Interaction with the scientific and development communities should
help move the processto one that will return more from our current financial inputs, and in
the future will attract even greater such inputs.
Nyle C. Brady
Senior International Development Counsultant
UNDP/IBRD
PREFACE
To: Dr. kMimn,
Mmagenzent
Director General, International Bad
for Soil Research cud
When we were asked to prepare this position paper we assumedit would be a relatively
straightfonvard task assemblingthe basic facts about the current state of knowledge of
how soil, water, and nutrients should be managed to sustain productivity and avoid
environmental damage..Given that there had been severalprevious efforts to assemblethe
same information, the task did not appear too daunting. We met to prepare an outline at
the International Board for Soil Researchand Management (IBSRAM) offrces in Bangkok
in September 1993. The outline presented a conventional and rather comprehensive
approach to the preparation of the position paper. It was circulated quite widely, and
discussedat a meeting of the Steering Committee in Washington, DC in October 1993.
The responsesreceived were divergent and conflicting, ranging from the need to broaden
the scopeto the need to sharpenthe focus, to give more attention to implementation but to
avoid proposing a strategy, and to concentrate on the farming systems but to use the
watershed as the basic component in the system. The one thing that was quite clear was
the keen interest in the topic.
We initially pursued a broad approach, on the basis that it would be easier to sharpen the
focus than broaden it at a later stage. As we assembled the material, it became
increasingly clear that we were restating technical problems and issues that had been
rehearsedin several earlier papers. It also becameevident that the conventional solutions
to the problems of soil, water, and nutrient management (SWNM) were making little
impact in the areas where needs were greatest, and environmental degradation was
proceeding unabated. Thus when we came together in Bangkok in February 1994 to
finalize the document, we felt that we had to concentrate on how existing scientific
knowledge of SWNM could be made to work for the community of farmers and others
living near the bottom of the unsustainabilityspiral and in danger of falling into the poverty
trap with very little hope of escape.
The goal statement and terms of reference conclude by stating that we should propose
strategies to improve resource managementand to addressthe identified problems more
efficiently. We have resisted the temptation to propose a strategy to provide additional
resources for SWNM, in spite of an increasing conviction that time was running out for
effective action to achieve positive results. We have confined ourselvesto the suggestion
that a mechanism be created to harmonize current activities, and prompt broader
interdisciplinary approachesin tackling the problems. We have identified the critical issue
as the failure to start the research processat the user level, and to establish a continuing
mechanismfor interchange of knowledge between the farmer and other practitioners and
the researchers. We may have given insufficient attention to the specific technical
problems of soil, water, nutrients, forestry, horticulture, and the managementof grazing
lands and vegetation. However, we feel that the basic changes in approach we are
suggestingapply to these and other topics,
In assessingthe relative significance of the problems, we found that the information
presently available on which to base a rational priormzation of research needs was not
adequate. A high priority must be given to assembling, analyzing, and making that
information available.
As part of the exercise,we circulated a simple questionnaireto various organizations and a
few individuals whom we thought were well informed of the problems. The responseswe
received strengthen our own conclusions that the greatest research need is to determine
how to make existing knowledge work for the user by giving more emphasisto adaptive
research,and greater attention to user perceptions.
The preparation of this paper has been an interesting but taxing exercise. At,the very end,
*we have inc!uded a subtitle - ‘A new agenda’- which was not what we were asked to
prepare, but what we firmly believe is needed. As with other proposals for change, we
expect a mixed reception as the contents are digestedand the new flavours tasted. We will
feel amply rewarded if even some small changesin funding arrangementsoccur which can
benefit the environment and the many millions who are at the base of the spiral of
unsustainabilityand perched on the edge of the poverty trap.
D.J. Greenland
G.D. B~,NII
H. Eswaran
R. Rhoades
C. Valentin
Bangkok, 3 March 1994
The goal statement and terms of reference
Goal statement
Prepare a position paper to:
* evaluatethe need for soil, water, and nutrient managementresearch,including
strategic, applied, and adaptive research;
* assesswhether current international capacitiesare adequateto addressthe major
issuesrelated to sustainableresource management;
* enhancethe interaction between the organizations involved in soil, water, and
nutrient managementresearch,and between such organizations and those involved
in other areasof researchrelated to sustainableland use and environmental impact;
and
* propose strategiesto improve resource managementresearch.
Terms of reference
1. Define the major problems of soil, water, and nutrient management (SWNM) in
relation to the sustainability of farming systemsand the effects of different systemsof
managementon natural resources. The definition should be based on previous studies
made of the need for international action to tackle the problems of SWNM and on the
information availablein existing data bases.
2. Define the major researchneedsto:
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ameliorate the problems of SWNM;
. realize the potential of SWNM resources;
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generatetechnology to increaseproduction;
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prevent further land degradation and deterioration of water resources;
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develop methods for transfer of technology between sites and between researcher
and farmer; and
evaluatethe impact of thesetechnologies.
3. identify policy issuesand social conditions which impact the amelioration of SWNM
problems or hinder the adoption of new technology.
4. Identify those problems for which new knowledge of the relevant principles exists to
provide a solution, but where it is still necessaryto integrate existing knowledge of
principles with indigenousknowledge and apply it to the local situation.
5. Propose priorities for future research,indicating where:
l
research addresses common global problems and may best be undertaken by
international organizations,and facilitated by better linkages between them; and
. research is primarily local-specific and may best be undertaken by national
organizations or national organizationsin liaison with international bodies.
6. Review the extent to which current international initiatives address:
l
the problems of SWNM; and
l
the capacities of national and international organizations to conduct the needed
research.
7. Propose strategiesby which the problems may be more efficiently addressed.
Executive Summary
l
l
l
l
l
l
At present there is no global strategy for researchon the problems of sustainableland
management,although there are many institutions concerned with specific aspects of
soil, water, and nutrient management. The ‘new agenda’of sustainability is an attempt
to conserve natural resources in the face of continuing pressures from population
growth and food demands. The problems to which these pressures give rise merit
urgent attention.
This position paper proposes a new scientific and development agenda to convert
existing soil, water, and nutrient management research into a relevant part of the
solution to the environmental crisis, rather than allow unwise policy, faulty research
systems,and inadequate farming practices to contribute to the problem. The ‘new
agenda’ is based on the premise that sustainable production systems can provide
adequate food and economic wealth, and at the same time conserve soil and water
resources effectively, which is a win-win situation. Where such systems are not in
place, there is a potential downward spiral of unsustainability,as increasing pressure is
put on land and water by human and animal populations.
For developing countries, and particularly the poorer of them, only through greater
productivity can the threat of environmental damagebe reduced. Attention must be
given to ensuring high productivity from stable soils, restoring and sustaining the
productivity of resilient soils, and conserving fragile and marginal soils. Necessary
measuresare best implementedon a communal basis.
Low rates of farmer adoption of improved managementpractices arising from policy
constraints, or a lack of adequate adaptive research, have frequently been the
stumbling .block. Unlike the relatively rapid adoption of improved crop varieties,
fertilizers, and pesticides,the adoption of contour strip-cropping, alley cropping, green
manuring, and conservation tillage have represented major challenges to farmer
operations, as they make increased demandson labour, capital, or land area. These
techniques are not readily translated from the technological improvements
demonstrated by scientific research into farmers’ practices, as they rely upon localspecific interpretation of the particular farmer needs.
We know how to make most soils yield more than they do at present. What we do not
know, in many cases,is how to make changeswhich are adapted to social, economic,
and political conditions in regions threatened by unsustainability. In this paper, we
propose a much closer association of farmers and technical advisers with the existing
research providers, so that farmer needs and decision-making constraints can be
incorporated into research directions, with an iterative feedback-feedforward process
to adjust the scientific principles of sustainable land and water management into
practical farmer realities.
By and large, the organizationsneededto conduct the necessaryresearchalready exist,
but the research is fragmented, inadequately focused on major problems, with little
coordination between different organizations - internationally, nationally, and nongovernmentally, Too little account is taken of farmers’ views, of indigenous know-
ledge, or of social and economic realities. Scientistsof different disciplines often find it
difficult to interact and work in multidisciplinary groups across agriculture, forestry,
ecology, anthropology, and economics.
.
l
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l
To overcome such institutional and cultural constraints to more effective implementation of soil and water research, we suggest a new research strategy which
acknowledges the need for a major shift in approaches, involving recognition of the
following:
l
Natural resource managementis a complex mix of biophysical and socioeconomic
factors.
t Government policy has a major role to play in effective land and water management.
+ Natural resources are not simply the base for higher yields of plants and animals,
but have significant contingencyvalue.
+ The methods neededfor sustainabi!ityresearch differ greatly from the procedures
of conventional agricultural research. Spatially, watersheds, villages, or regional
scalesof operation may be needed, while the longer time scales of sustainability
issuesrequire combinationsof simulation modeiling and reference-sitemonitoring.
While the farming system is the level at which most soil, water, and nutrient
managementpractices have to be implemented, the large number of local systemsand
farming communities make it difficult for national as well as international organizations
to devise improved sustainable systems suited to all. We believe that the most
satisfactory approach to this problem is through the formation of ‘consortia’ in which
all those with relevant interests and expertiseare involved.
To support the development and operations of the consortia, we suggest that a
facilitating organization be establishedwhich, for want of a better name, we refer to as
a ‘clearing house’. The ‘clearing house’would provide the mechanismfor harmonizing
the activities of the many organizations involved, acting as a centre that would ensure
that necessary information was shared between participants, and supporting the
training activities of the consortia. We see that training will have an extremely
importani role in the application of sustainableland and water managementpractices,
becausethe holistic approach required meansthat there is a larger demand for training
and education in areasoutside each individual’s existing area of expertise.
While the views of the national programmes must be paramount in determining how
land and water managementis conducted in their respective countries, we believe that
the complexity and diversity of the problems implies that an international ‘clearing
house’will have a comparative advantagein supporting and facilitating the work of the
consortia, and ensuring that results are shared amongst different organizations, duplication is reduced, priority-setting is properly established, and accountability is
satisfied.
I
SWNM AND THE CHALLENGE OF SUSTAINABILITY
“We are, during the closing decadesof the twentieth cetltury, approaching the end of the
most remarkable transition in the history of agriculture. Before the beginning of this
century almost all the increases in agricultural production occurred as a result of
increases in the area cultisated. By the end of the century there will be f2w sig@ant
areas where agricultural production can be expanded by simply adding more iand to
production. Agricuiturai output will have to be expanded aimost ejltirely from more
intensive cultivation irr areas ‘already being usedfor agricultural production. ” (V. W.
Ruttan, 1987)
01
A number of factors have combined to refocus attention on the problems of soil,
water, and nutrient managementin developing countries. In 1992 at the UN Conference
on Environment and Development (UNCED), Agenda 21 drew attention to the many
problems of developmentin relation to environmental degradation. Agenda 21 noted that
most of the problems Brose from the exploitation of soil and water resources induced by
the need to produce more to meet the needsof a growing population. The importance of
managing resources so that they were neither degraded nor depleted received strong
emphasis. Land must be managed sustainablyif it is to feed, clothe, and provide for the
other needsof the community - not only now but for many years to come.
02
Undoubtedly soil degradation has been occurring widely in the past few decades.
This has effected yields and also the wider environment. A recent assessmentof global soil
degradation (Oldeman ef al., 1990) presents a collection of data based on national
appraisals,mostly rather subjective, and considers the extent of soil degradation due to
different processes. While there is a need for a more detailed and objective study of the
extent of the damage and its reversibility, the study makes it absolutely clear that better
appraisalof the seriousnessof the situation is required. It is not only land that is subject to
damage. Damage to water-storage and distribution facilities and other off-site damage
associated with soil erosion are giving new impetus to the importance of changes
occurring on a watershed scaleand on a scalewhich is larger than the watershed. Some of
these changes occur slowly, and their significance can only be recognized when care&l
studiesare pursued over severaldecades.
03
Although of less immediate concern, the potential effects of climate change on
terrestrial ecosystems and their interaction with land-use changes also have to be
recognized. There is good reason to believe that intensified land-use systems are
contributing to climatic changes. Undoubtedly a need exists for better coordination of
studies being conducted on the global significance of climate change and of the studies
neededto intensify and sustainagricultural production and other land-usepractices.
04
At the 1993 meeting of the Consultative Group for International Agricultural
Research (CGIAR) in Washington, Per Pinstrup-Anderson, director general of the
International Food Policy Research Institute (IFPRI), gave a realistic appraisal of the
present world food ,position and of future prospects. While acknowledging the major
gains made in iecent years, the paper recognizedthat malnutrition is still prevalent in many
countries, that stagnating per caput yields of the major cereals poses a serious challenge,
G
and that there is a pressing need to develop. more productive and sustainable land
managementmethods.
05
At the Food and Agriculture Organization of the United Nations (FAO) meeting of
the Council of Ministers the following week, Agricdfuw Towcztds2010 (FAO, 1993a)
was released, again recognizing recent progress in the world food situation, but also
making very clear the seriousness of food production problems in many developing
countries in relation to the sustainabilityof natural resources,the dwindling resource base,
and the overall decreasein the rates at which productivity has grown. Both the IFPRI and
FAO reviews addressedthe problem on a global scale. At the national level there are
many countries where the problems of food production are already serious, as the FAO
study shows. In several countries stagnating or dechtiing yields reflect declining soil
fertility and the continuing expansionof cultivated areasonto marginal land. Problems are
also emerging in some of the more productive irrigated areas. In specific regions within
countries, there are problems which are much more serious than those in the country as a
whole.
Underlying the problem of sustainable land management is the problem of
06
increasing demographic pressure on the land resource. At the present time, the annual
population increaseis greater than it has ever been, and probably greater than it ever will
be in the future. Although the world continues to be able to produce sufficient food ?o
feed its burgeoning population, it is not always able to supply this food to the places where
it is most needed. Where extra production has been achieved, it has been obtained by
increasing yields using fertilizers, expandingthe use of water for irrigation, growing cro;,
varieties able to respond to higher inputs, and cultivating more land. The additional land
was obtained by deforestation, or by using land under restorative fallow - or previously
under rough grazing becauseit was consideredunsuitable, or only marginally suitable, for
cultivation.
The symptoms of unsustainability
07
The question - unsuccessfbllyaddressedin the past - was how to raise yie& on a
per hectare basis. Greater production can be obtained by cultivating more land, or by
cultivating existing land more frequently. The question that must now be addressed,and
which is giving rise to serious concern, is whether we can continue to extend and intensi@
production sustainably. The reasons for concern are the declining and stagnating yields
per unit of input (and in some casesper unit of land), the declining quantity and quality of
land resources, declining water resources, declining soil nutrient reserves, and various
forms of environmental degradation. Much has been written about these issues, and we
will not review them here. A synopsisis given in Annex I.
For many, the problems we have outlined are now a matter of life and death. What
08
unsustainability meansto the individual farmer and his family in many of the poorer areas
of shifting cultivation is that the land he or she is now cultivating fails to yield, and the
fallow land to which the family would previously have shifted is already occupied by
another farmer. Many farmers are faced with a choice of joining the mass of migrant
labour moving to the city (adding to the mass of shanty-town dwellers}, or moving to
wherever they can find land - usually leading to conflict with those who had declared the
land a forest reserve or with those who considered they had a traditional right to that land
when their own becameexhausted.In some of the irrigated areas,the farmer is finding that
the irrigation water on which he dependsno longer arrives when he needsit becausethere
is insufficient water in the reservoir. Yields may also be unexpectedly declining even
though high-yielding cultivars have been planted and fertilizer applied - the hidden cause
being rising saiinization.
09
The remedies offered by modern technology, involving a range of improved soil,
water, and nutrient managementmethods may be capable of producing sufficient yields.
What is less certain is whether their use is known in the area, whether the needed inputs
are available, and whether their use i.s economic. Finding ways to remedy the human
problems of poverty must be a high priority in dealing with unsustainability.
10
The national average yields of the majoi staples in several countries in Africa are
now abysmallylow. Maize yields in Angola and Mozambique are now below 400 kg ha-l,
as are those of sorghum and millet in Niger. In the Sudan, the average annual yield of
millet for the years 1989 to 1991 was only 166 kg ha-l. Between 1960 and 1970, the yield
of cassavain Zaire was more than 12 t ha-l, but is now about 7 t ha-l. It is often suggested
that this is a result of civil strife. In fact, in most of the countries where strife is occurring,
yields have been failing since FAO first reported national yield levels in 1960, well before
current problems of internal warfare started. The declining yields are certainly a result of
deterioration of soil conditions and the expansionof production onto more marginal soils.
Political and socioeconomicconditions frustrate attempts to rectify the situation.
Management for sustainability
II
Yields can be enhanced by improving the characteristics of the plant and by
improving the suitability of the environment for the growth of the plant. Genetic
improvement hasbeen a major and highly sudcessfU1
strategy in yield improvement (Evans,
1993). The advancesin gene manipulation and other areas of biotechnology will ensure
continuing advancesin crop improvement. When plant varieties which are adapted to the
environment in which they are to be grown, and which have greater yield potential and
pest resistance than those in current use have become available, there have been no
problems of farmer acceptanceand adoption.
12
To realize the advantagesof the improved varieties to the full, it has usually been
necessaryto improve the plant environment by the use of irrigation water and fertilizers.
While the improvement in plant type, the spread of irrigation, and the increasein fertilizer
use are likely to remain basic factors in the continuing ability of the world to feed, clothe,
and provide fuel and buiIding materials for a growing population, the problem that still has
to be tackled in many parts of the developing world is how to integrate these factors into
viable economic packagesfor farmers and other land users.
In order to create sustainablesystems,more attention must first be focused on the
13
human dimensionsof the problems, the wider environmental effects of land-use changes,
and the number of decadesrequired for the sustainabilityof the changesto be established.
8
14 . Any land-use system is unsustainableif it leads to irreversible biophysical changes
in the ability of the land to produce equally well in a future cycle of similar land use, or if
the costs of reversing the changes are prohibitive. Thus the unsustainability may be
biophysical or economic. Sustainable land management is “combining technologies,
policies and activities aimed at integrating socioeconomic principles with environmental
concernsso as to simultaneously:
. maintain or enhanceproduction/services;
l
reduce the level of production risk;
l
protect the potential of natural resources and prevent degradation of soil and
water quality;
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be economicallyviable;
(Dumanski, 1993)~
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be socially acceptable”.
The managementof land must aim to satisfy these criteria - a task which is made
15
more difftcult when demands on the land are increasing rapidly. Historically, there have
been only three methods by which sustainableagricultural productivity has been obtained,
eachbasedon the restoration of soil fertility after cultivation. They are:
. shifting cultivation systems;
l
animal-basedfarming systems;and
. water-based systemsfor rice production.
16
Each of these systemshas been viable as long as the demandsmade on the system
were low and the land was plentiful. Larger populations could only be supported when the
discovery of inorganic fertilizers enabled nutrients removed in crops to be not only
replenishedbut actually to be raised to much higher levels.
17
In some areas, greater yields have been obtained by controlling water supplies
through the construction of reservoirs, water distribution systems,and greatly expanded
use of fertilizers, sometimessupplementedby manures. While in several countries yields
continue to increase, in others doubts about the sustainability of some cropping systems,
such as the rice-wheat systems,have been raised becauseof falling productivity and water
supply and distribution problems. In areaswhere shifting cultivation and extensive mixed
farming are still the principal form of agriculture (mostly, but by no meansexclusively, the
forest and savannaareas of Africa), the response to growing demographic pressure has
been to bring land lying fallow into cultivation before fertility has been restored, or to
cultivate marginal land only suitable for extensivegrazing or to be left under forest. This
has almost always involved the use of land of lower fertility, which is more readily subject
to degradation. At this stage a downhill cycle of unsustainabilitycommences(Figure 1.1).
18
Many long-term experiments have been conducted in developing countries to
examine the productivity and sustainability of farming systems. Data from long-term
experimentsin West Africa conducted for two decadesor more show that while inorganic
fertilizers can reverse the decline in the early years of cultivation, they will not do so
indefinitely (Pieri, 1992). Problems of acidity, nutrient balance, and other factors must
also be corrected. To correct these factors, the only practicable method for the great
majority of smallfarmersin West Africa is to combine the use of inorganic fertilizers with
some method by which levels of soil organic matter can be maintained.
Nutrient
Low
-
hv
yields
iIlCOIllC
-
Low inputs
Figure I.1 The domnlxxrd spiral of the poverty trap (McCow and Jones, 1992).
The role of interlatioqal
organizations in soil, water, and nutrient management
19
The response of the international community at the time of the threatened food
.
crisis of the 1960swas to establishIARCs supported by the CGIAR.
20
The strong focus on improved crop varieties, allied to well-established high-input
methods to increase yields, proved highly successtil in removing the threat of an
international food crisis. The limitations and inapplicability of the methods for certain
conditions, and the threats now posed to the environment, have emerged in the course of
the past two decades. The need to address these environmental problems has been
recognized by the international system in the acceptancethat some of the CGIAR centres
should have an ‘ecoregional’mandate,with a stronger focus on environmentalproblems.
IBSlUM
and the International Fertilizer Development Centre (IFDC) were created
21
to assist national organizations in tackling problems related to sustainablesoil, water, and
nutrient management.The Tropical Soil Biology and Fertility (TSBF) programme has also
been established,recognizing the importance of soil biology to the sustained.,andeffiient
productivity
of agriculture
in the tropics.
Further, in response to the problems which may
10
arise from global climate change,the Global Change and Terrestrial Ecosystems (GCTE)
project has been establishedunder the auspicesof the International Council of Scientific
Unions (ICSU).
22
Several UN organizations, notably FAO, UNEP, and CTilESCO, have been
strongly involved in many aspects of SWNM, in relation both to productivity increases,
environmental problems, and the expansion of the knowledge base on which successful
development depends. Researchof national institutions in the developed world and some
of their international programmes, such as those of ORSTOM (France) and the
collaborative research support programmes of USAID, have added considerable
information to ihis knowledge base.
Aims of the present paper: problem identification
23
Much information is available regarding the specific problems of sdil productivity,
of water management, and of methods to preserve the resource base. Of particular
relevanceare the papersprepared for the Technical Advisory Committee (TAC) by Pereira
ef nl. (1979) and Sanchezand Nicholaides (1981), and for the meeting on Prioriks.for
Relieving Soil-related Consfrainfs to Food Production in ihe Copies (IRRI, 1981).
These papers and the report of the soil-related constraints meeting define fully the
problems of SWNM as they existed at that time and as they now exist. The extra
dimensionswhich have emerged in the subsequentyears have related to the needs to give
more attention to the environmentally related aspects, widening the time and spatial
dimensions which must be considered. The importance of the socioeconomic factors
which “must be taken into account” in generating sustainablemethods of SWNM was also
noted, although the full significance was only recognized in the paper relating to water
managementprepared by Pereira and his colleagues.
24
At the soil-related constraints meeting, the need to make better use of the
biophysical knowledge of soils was recognized, and led ultimately to the establishmentof
IBSRAM with its clearly stated purpose of supporting NARS in the.conduct of adaptive
soils research.
25
In the past decade, it has become increasingly clear that while we have
accumulated a great deal about knowledge of biophysicai and socioeconomic f&ctors
related to land use and SWNM, and have succeededin using that knowledge to increase
production in favourable situations, we have been remarkably inept in applying that
knowledge to the development and implementation of more productive and sustainable
land managementsystemsfor less-favouredareas. We believe that the ineffectivenesslies
in the divorce of the research agenda from the real problems of unsustainability as they
affect the land user - farmer, forester, or pastoralist - in the field. The challenge is to make
the solutions work for the smallfaimer.
The problems we identify are not those of conventionalbiophysical soil research,of
26
which sufficient has already been written, but of integrating research on socioeconomic
issues and biophysical processesinto SWNM studies for the end-purpose of designing
practical, operational approachesfor the implementationof improved SWNM.
11
II
AN INTEGRATED APPROACH TO SWNM
27
Creating sustainableagricultural and natural resource management systems from
unsustainableones can only be achievedby finding solutions to whole-system deficiencies
as well.as to component problems. It is titile to attack only technical problems - as has
been common in the past - without addressingthe overall pattern of degradation causedby
socioeconomic pressures.Human behaviour driven by poverty, population dynamics, and
myopic government economic and land policies is the underlying cause of land and water
degradation. A future researchagendafor SWNM must therefore offer a way in which the
social, economic, and policy issuesand biophysicalprocessesare linked.
The cycle of unsustainability
28
Visualizing unsustainability as a ‘process’ can illustrate how many agricultural
systemsbecome locked into a degeneratingspiral driven by interlinked socioeconomicand
biophysical factors. Although the process will vary from place to p&e, a generalized
‘cycle of unsustainability’ (Figure II.]) can be identified, as can its components. Both
biophysical and socioeconomicproblems play key roles in the process, each feeding on the
other.
Inappropriate
technologies(2) Pressure on marginal lands: agicultural
degradation
SBUC1tlR
(1 j Increasing
long-term
Limited cmploymenr
production
population
investment
t
(6) Lack of.capilal
:,
:
\
Net
.
resource
now
(5) Poor pricing, credit, policies,
centralized decision-making
Wafer resource
degradation
t
Inadequate knowledge
sgstcms
Outmigtation
of labour
*
Figure II. 1 The cycle of unsustainabiIiiy (Rhoadesand Hanwod, 1992).
12
Loss of
agricultural land
29
The processesunderlying the unsustainabilitycycle (Rhoades and Harwood, 1992)
are:
l
An expanding rural population places pressure on urban and rural environments,
especiallymarginal areas(uplands, rainforests, deserts,and wetlands) where land is still
available and land prices are low.
l
Pressure on this production base and marginal enviroc:nents are exacerbated by
structured inequities in returns to agriculture and fanners’ and governments’ needs to
meet short-term survival goals.
l
Simultaneously, pressures in favoured areas, such as irrigated and fertile coastal
lowlands, grow from:
+ inappropriate land use in adjacent marginal areas, creating unevennessof water
flow (surges, flooding, and runoff) to lower elevations,and increasedsilt and other
containment loading;
+ water and land resources as a result of competing urban uses and poor
managementresulting in uneven distribution, salinization, and waterlogging;
4 increasedland and water pollution from chemical-dependenturban agricultural and
nonagricultural pollution; and
* rapid urbanization.
l
Due to rapid changesin all farming systems,scientific and indigenous knowledge alike
become inadequateto meet a society’sand users’ (farmers’, foresters’, or pastoralists’)
needs.
L Driving the unsustainabilitycycle are ill-advised pricing-credit policies and land policies
which work againstlong-term investmentbecause:
t pricing policies may change unpredictably, while international pricing (subsidies)
may undermine returns to local agriculture;
l
land-use policies, including tenure and rights, provide incentives for unsustainable
land and water use;
+ political bias and expediency, especially the undervaluation of food, cause a net
flow of resources out of rural areas, which in turn leads to further rural impoverishment; and
t neglect of investment in the rural sector is accompaniedby centralization of natural
resource management and bureaucratic control of resources, which leads to
nonloca! development planning and a consequentreduction in local responsibility
and incentives.
l
Given the undervaluation of the rural sector, society (politicians) are reluctant to invest
in the three types of ‘capital’ required to turn soil, water, and nutrient unsustainability
around:
+ the physical infrastructure for irrigation and drainage systems, terraces, dams,
waterways, wells, etc. which usually requires a cash investment with’ credit at
reasonablecost;
t biological capital, which is investment in long-term produclion through planting
trees and other perennials,building organic matter, etc., and can be generated by
local people by giving them land rights, access to other resources, and social
stability; and
+ human capital, which is investment in people and their social institutions at all
levels for purposes of creating better-educated citizens, better national scientists,
and better local developmentworkers.
. Finally a disenfranchised rural population degrading and inappropriately using
resources fLrther reduces production potential and thus the ability to correct factors
13
that lead to poverty. The poverty cycle deepens, leading to an increase in social
instability, decreased investment and productivity, and fiu-ther soil and water
degradation.
The need for new models and methods
Reversing the above cycle will require an integrated research strategy involving
30
new models, methods, and institutional arrangementssignificantly different from earlier
production approaches.Four major reasonsaccount for this required shift:
l
Natural resources are no longer perceived by the scientific or policy
communities as merely the medium to produce more food through high yields
of plants and animals, but rather in terms of local and global ecosystem
functioning. In addition to contingent values (production output), noncontingent values (ecosystem maintenance,biodiversity, water recharge, clean air,
even sacrednessand bequeath value) become important topics in the research
effort. Conventional scienceis poorly equipped to deal with these ‘ecological’
and ethical arguments.
l
Comparedto crop and pest management,natural resource managementis more
complicatedtechnically and manageriallyfor both farmers and scientists.Natural resource scienceis in its infancy compared to such disciplines as genetics,
crop physiology, or even agricultural economics. It involves a greater number
of systematic relationships which are highly interactive. One land user can
impact the health and production of many others. This complexity of natural
resource systemsalso raisesthe new issueof linkages within sociopolitical hierarchiesand scalesof intervention.
l
Conventional policy tools are deficient in their ability to manage, regulate, and
encourage sustainable use of natural resources. Despite the often-heard
statement that governments have longer planning horizons than farmers,
officials and state bodies have their own agenda which may counter the longterm interests of sustainabledevelopmentat the local level.
l
Sustainability raises new issues such as time and spatial dimensions, social
hierarchies, and societal vs. individual benefits, and therefore requires new
approachesto solving problems. Although lessons can be learnt from farming
systemsresearch (FSR), the goals of FSR and earlier approaches differ from
those of natural resource managementresearch (NRMR), including SWNM
research(Table II. 1). A consideration of the temporal, spatial, and beneficiary
dimensionswill illustrate the difference.
Temporal dimensions of sustainability
Sustainability requires that time frames well beyond annual cropping cycles are
31
studied. Three diachronic issuesarise:
. the need to learn from the past;
l
perceptions of impacts of current practices(good and bad) on the future; and
. intergenerational issues,wherein payoffs may not come in the lifetime of the
community or farm household which implements a practice but to fLture
generations.
Table II. 1 Selectedcomparison
of approaches:
croppingsystems,
FSR,andNRMR.
Parameler
Croppingsystems
Temporal
Spatial
BeneficiaF
Technology
Target
Annualcycle
Fieid-plot
Farmer
Component
Self-sufliciency
FSRt
l-3 year cycle
NRMR#
S-25 years
Watershed-region
Field-village
Multiple
Family
Farm production
system Naturalrcsourccsystem
Profits
Moneta~lllonmonetary
intcrgcnentionalequity
Recipientof technology Providerof information Participatory
Roleof farmer
Multiple
Marketing
Policy
Input/prices
Marginal,on-site
Maximum on- and off-site
Environmental
concern Minimal,on-site
research
t FSR = Farmingsystems
2 NRMR= Naturalresource
management
research
Degradation of natural resources often occurs gradually so that each generation
only glimpses part of the historic process. The outcome is not known in advance. Slowly,
people adapt to negative changes, which in turn accelerate fiu-ther degradation, until
disasterbecomesdiscernible.
In many traditional, closed corporate communities intergenerational equity or
32
‘bequeathvalue’ is as important as it is in developed countries where famlers expect their
families to continue to farm their land long into the future. Indigenous communities with a
‘senseof place’ 2-e aware of the value of land, and strive toward long-term sustainability.
Andean Indian communities, for instance, carefully regulate, through village assemblies,
the rotations of land parcels,the use of communal pastures,the cleaning and maintenance
of irrigation channels,herd size, and even the types of crops planted. External exploitation
of land is limited, since only members of the community have inheritance rights to land.
Problems in these systems arise as population pressure and penetration of commercial
markets stimulate the breakdown of traditional land-use systems (Malcolm, 1993;
DANIDA, 1989).
33
Tenancy arrangementswhich give no permanentrights can result in suboptimal use
and managementof natural resources (Southgate, 1988). Tenants are simply unwilling to
incur short-term costs for the sake of benefits which will occur after the tenancy ends.
Without right to land in perpetuity, farmers are reluctant to invest in the future Similarly,
‘slash-and-burn’practiced by displaced persons without title to the invaded land is often
extremely destructive. In such situations, policies which enable individual title to be
establishedcan result in land improvement.
Even if small-scalefarmers are aware of the benefits which may occur in the longer
term from changesin their practices, such as those designedto limit erosion or increase
soil organic-matter, they do not give them high priority becausethey occur over a time
horizon not relevant to their immediate needs (Izac, 1992). Changes which give an
immediate and obvious return, such as the introduction of fertilizers with an improved
responsive crop variety for which a ready market exists, stand a much better chance of
adoption. Farmer interest in short- rather than long-term benefits is of course by no means
unique to developing countries. The sustainability of farming in western Europe needed.
34
15
government subsidiesfor drainage and liming of soils to make it secure, and in the USA
government support for erosion-control measureswas needed before they were widely
adopted.
Who benefits: society or the individual?
35
Many societal benefits arising from improved SWNM (e.g. reductions in siltation
and flood damage,enhancedbiodiversity, reduced water pollution) occur beyond the farm
gate, at the level of village, region, and nation. For instance, measures to increase the
organic-matter content of the soil often have limited immediate benefit to the farmer - the
extra nitrogen can usually be obtained more cheaplyfrom fertilizers - but more substantial
benefitsto the farmer and the community are likely to arise over a longer time scale (Table
II.2, adaptedfrom Swift el nl., 1994).
Table 11.2: Individual and social benefits of soil managementpractices.
Benefits
Time
6-10 years
1l-50 years
1 year
2-5 years
+-+
++
Uf
+++
0
0
+
0
f-k
+
u-6
++
0
0
0
+
+o
+
+
++
++
+t
+++
+++
Monetary and individual benefits
Increasedyields through increasedsoil fertility
Nonmonetary, individual, and social benegts
Increasedsustainability of systemthrough:
- reduced risk of yield fluctuations with
manual climatic variability
- enhanced soil resourcebase
- enhancedcapacity of system to adjust lo
exogenouschangeswithout generating
increasedflows of pollutants
- increasedbiodiversity of soil biota
- reduced risk of erosion
Note: 0 = no measurablebenefit,
+, +-I-,+++ = measuredbenefit, with intensity of benefit ranging from low (i) IO high (+++).
36
Given that voluntary adoption by individual farmers may often be socially
suboptimal, policy intervention is needed.Policies used in developed countries are difficult
to implement in developing countries (e.g. regulations are difficult to enforce; taxes and
subsidiesare costly to administrate). Price policy (reducing prices for inputs, support for
conservation crops), land reform, food for work, and direct community incentives have
been attempted with mixed results (Izac and Swift, 1992). Direct incentives, for example,
may instil the belief in farmers that conservation is something someone else pays for and
benefits others insteadof themselves.
India is encouraging farmers to form their own ‘land-use associations’, where
31
available land is classified into (i) conservation areas (ii) restoration areas, and (iii)
sustainableintensification areas (Swaminathan, 1994). Similar action adopted elsewhere
would meet the wider’ need for communities to manage their land and water resources
effectively. The formation of such groups can be greatly encouraged by linking them with
16
land tenure rights (Cernea, 1987; Moorehead, 1989). Community-based support has low
implementation costs: the community can share risks, communal arrangementsare implemented in simple ways, and economiesof scaleare realized by pooling resources of labour
and capital. By basing operations on the community, the results are more likely to be
adapted to local ecological landscapes,as they effect the whole village area and not the
fields of an individual farmer (Izac, 1994).
Social hierarchies and spatial dimensions: multiple clients
38
Unlike conventional crop and livestock improvement in which researchersstudy a
component or systemon a relatively small-scale(plot, field, agroecolog?caizone), SWNhl
needsto deal with a much broader range of interacting hierarchical levels, including households, village communities, irrigation societies, tribal groups, provincial governments,
nation states, and even larger entities. These increasingly complex social units reflect the
larger spatial units which have to be considered- ranging from the plot, the catchment, or
watershed to the wider landscape and to the geographic boundaries of nation states.
SuccessfulSWNM will require intervention at eachof these levels to achieveresults.
39
Much confusion in sustainability research derives from researchers studying
different scalesand then mixing levels in analysis.Each level requires its own analysis to
permit systematic scaling up or down between levels. The catchment, for example, is the
hydrologically determined unit of regulation of water, nutrient, and sediment flow over the
landscape.It integrates the overall environmental effects of the mosaic of vegetation and
land uses, and is. a logical sca!e for interdisciplinary efforts to improve environmental
managementand the conservation of resources.
40
The relationship between rangeland management,forestry, and hydrology has also
to be included in this consideration. However, many soil scientists work at the level of
constituents of the pedon, agronomistsat the plot level, anthropologists at the village level,
and economists at the scale of regional markets. Recognition of how different levels link
must be central to any integrated designfor SWNM.
41
The farming system is probably the most realistic level at which to operationalize
sustainability (Lynam and Herdt, 1992; Izac and Swift, 1992). As the smallest scale where
biological, economic, and social considerationsare integrated, householdsmake decisions
concerning the distribution and allocation of resources between different components.
Often such allocations of human and financial resources also involve transfers of energy
and nutrients between levels. A farmer manipulatesavailableresources,which may include
resources on the farm (crop residues), imported from elsewhere in the watershed
(manure), or purchased from outside (fertilizers). These interactions of decisions, along
with those concerning irrigation, drainage, tillage, and mechanization, are all part of a
given soil managementstrategy. The benefits of using one technique rather than another
must be set against the value of the resource for other uses (e.g. fodder for fuel or
livestock instead of soil enhancement), and the benefits of allocating labour to soil
managementrather than taking advantageof other opportunities (Izac and Swift, 1992).
17
A user-participatory approach to SWNM
42
An approach to solving problems at the farming system or catchment level must
incorporate the factors of time, hierarchy, benefits, and costs in such a way that
sustainability is enhanced, as measured by spatially and socially determined baseline
indicators. This implies a participatory approach involving farmers, policy-makers, NGOs,
scientists, and others within the zone of influence. If recommended SWNM technologies
are not being used, it is seldom due to farmer ignorance, but to a flaw in the technologygeneration process. Natural resource methodology must be multiperspective, drawing on
ecology and systems analysis, natural-resource economics, and indigenous knowledge
sought through anthropological studies.
43
Feedbackmust be provided to the researcher,and flow through the whole research
chain from adaptive to basic research (Figure 11.2). This is not to deny a place for
curiosity-driven basic research, or to suggest that targeted research (primarily using new
knowledge coming from basic research) cannot make a contribution. It is possible, for
instance, that the largest contribution to most farming systems may come from basic
studies of the enzymatic processes of nitrogen fixation. But in applying and adapting
existing knowledge, little progress is likely without an integrated approach in which land
users and researchersfrom different disciplines are involved from the earliest stage of the
research-planning process. The farmer-back-to-farmer paradigm (Rhoades and Booth,
1982) provides a basisfor conducting researchin this way (see Annex IV and Figure 11.3).
Discipliicoricntcd
research
.kiCfiCC-
General *
purposcoriented
research
Mission-
Specific
purposeoriented
research
Figure 11.2 Building and eschanging knowledge of SWNM.
18
LOGU.iOIl-
oriented
research
I.
.....“--v.*
.--.---.-
--
Participatorydiagnosis:
Scientistand user
indigenousknowledge
- technicalappraisal
.
l
environmental
:ment
\
SWNM
I
definition
I
/
\
III. Adapting/testing
on-farm research
Off-farmimpact
environmentalimpacts
relevance
SWNM
I
/
II. Seekingsolutions
resourcecharacterization
systemnutrient flows
socioe.conomics
farmerdecision-making
l
l
l
l
l
l
l
on-farm research
resourcemapping
l
social
l
Figure II.3 The farmer-back-to-farmer adaptive researchmodeI.
Nine principles to reverse the unsustainability cycle
44
A new approach is called for in which national and international organizations
work in a unified manner on both socioeconomicand biophysical problems to deal with the
system deficienciesof the cycle of unsustainability.Nine basic principles should guide this
new effort.
45
Principle one. Contributions of research organizations are only valuable to the
degree that they ultimately address real points along the cycle of unsustainability. For
example, refining soil typologies for scientific study is seldom relevant to solving the
problems of sustainability.
46
Principle two. It is legitimate for SWNM specialiststo attack ‘problems’(technical
or socioeconomic) at any point in the cycle of unsustainability as long as the proposed
solutions are understood not to stand alone, and can only succeedif other closely linked
problems/processesare addressed. For example, erosion-control engineering must be
linked with cropping patterns and economicincentives.
47
Principle three. The systematicnature of the cycle demandsthat scientistsbe part
of broadly interdisciplinary teams, and that research organizations be multi- and interdisciplinary. A prerequisite must be that trying to correct ‘symptoms’ of unsustainability
19
(e.g., gullies and polluted water) must be part of a deeper, more theoretically sophisticated
analysisinvolving all relevant sciences.
48
Principle four. The most appropriate research scale is at the watershed or
catchment level, although researchat the plot, field, cropping system, or regional level is
legitimate - and must be related to the ‘cycle of unsustainability’,which is driven by forces
operating on a larger scale.
Principle five. While SWNM researchers realize that some processes in the
49
unsustainability cycle are beyond their direct influence (e.g. urban sprawl, global
commodity trade, and national land policies), there is a continual obligation to raise
awarenessamong donors, policy-makers, and government off;ciaIs that technical problems
cannot be solved in isolation.
Principle six. Platforms of negotiation between scibntific understanding and local
50
folk knowledge (in&din, 0 that of women) of SWNM must be constructed. This will
combine, at the watershed level, knowledge of the ‘reality’ and particulars of the reality
with the power of science,including results obtained in distant researchsites.
51
Principle seven. Researchmust be a much longer-term proposition than conventional agricultural research, but it must neverthelessstill address points along the cycle.
Impact can rarely be expectedfrom short-term projects.
52
Principle eight. Technical solutions cannot be generated in laboratories or
experiment stations isolated from real-life conditions - and then ‘sit on shelves’awaiting
ungratefL1farmers. The processmust be reversed.The mythical ‘shelves’must be replaced
with palatable technology ‘cafeterias’,in which solution-hungry farmers select and taste to
their liking (see the farmer-back-to-farmer model in Figure 11.2).
53
Principle nine. SWNM researchers should not work in isolation, but should
benefit from comparative, common workplans which reach across well-selected global
sites where long-term experiments are being conducted. This principle implies development of a global network of researchers,organizations, and projects, in which everyone
understandshow his efforts fit into a global plan to reversethe ‘cycle of unsustainability’.
54
By following the above nine principles it should be possible to develop research
programmesby which the cycle of increasingunsustainabilitycan be gradually transformed
into a cycle of sustainability. These sustainablesystemswill be characterized nor only by a
population in balance with its resource base, but also by agricultural systemswhich blend
with the environment, provide clean water, regenerate soils, give a fair return on land,
labour, and capital to the farmer, enjoy decentralizeddecision-making, and offer research
potential for the agrarian sector. While this may sound like a pipe dream, failure to reach
for the dream could spell disasterfor the global village.
20
III
SWNM RESEARCH: NEW DIMENSIONS.
55
Why is it that it has not been possible to develop technology to help less wellendowed areas commonly encountered in tropical countries? Varieties of most crop
species with at least partial tolerance to adverse conditions and much-improved yield
potentials are already available, but have seldom had an impact on productivity in these
areas. Methods of soil, water, and nutrient management to increase productivity are
available for many areas, but most of them are not adopted - mostly becausethey lack
social and economic viability. The solution to the economic limitations may be to make
changesin policy; but the reality in many countries is that policy will not be easily changed,
and better-adapted technology must be sought through tirther research (Crosson and
Anders,on, 1992). A brief discussion of the research opportunities given below is
elaborated in Annex III.
Components of SWNM research
Plant mfrienfs. Responsible husbandry of plant nutrients, avoiding nutrient
56
mining, is a major key to sustainedproductivity at both the farm and national level. Traditionally, replenishmentof nutrients removed in crops has been by nutrient redistribution
through animals, trees, or water. Such transfers are now generally unable to restore the
higher rates of removal required for current food, fuel, and flbre needs. In Africa at the
present time, removal rates far exceed replenishment rates (Figure 111.1).There is no
escapefrom having to supply nutrients removed in crops, or lost by leaching or erosion,
from other sources- most commonly and cheaply from inorganic fertilizers. In developed
countries, problems from excessive use of fertilizers and other agricultural inputs are
widespread. In developedcountries, such problems are mostly confined to limited areasin
certain countries. In Africa, for instance, the average per hectare inputs of inorganic
fertilizers are of the ,order of 10 kg ha-r, as compared with the rate in Europe (exceeding
500 kg ha-r).
I
1
Fallow
LOSSES
I-J
Erosion
Nitrogen
Phosphorus
Potassium
,:.
Figure III.1 Nutrient balance for sub-SaharanAfrica (Stangel et al., 1993)
21
The challenge is to provide farmers with fertilizers at economic prices, and to
57
ensurethat fertilizers are used as efficiently and effectively as possible. At the applied and
adaptive research level, there is still scope for location-specific studies of timing,
placementmethods, and residual values of applied nutrients. At the applied and strategic
levels, there is considerable scope for plant studies on the efficiency of nutrient use,
managementin agroforestry, relay- and multiple-cropping systems,and adapting fertilizer
practicesto water availability as indicated by long-range weather forecasting.
58
A key component in efficient nutrient managementis the use made of nitrogenfixing pasture plants and grain and tree legumes. There is no doubt that the quantity of
nitrogen supplied by fixation could be increasedconsiderablyin many areasby inoculation
technology suitably tailored to local needs, the selection of inoculants to compete
effectively with less-efficient local strains, and the selection of genotypes with high
nitrogen-fixation capacity.
Soil wafer. The second pillar of productivity and sustainability is the proper
59
managementof soil water. Soils have to be managedto ensurethat sufficient water enters
and is stored in the soil for crop growth. There is, of course, a strong interaction between
water and nutrients in their effects on crop production. Researchagain requires synergism
between soil and plant scientists. In drier areas,managementto improve water-harvesting,
e.g. by establishing microcatchments and developing appropriate tillage methods, is
needed,together with the production and managementof organic matter on and in the soil.
To increasethe effectivenessof water use in both rainfed and irrigated systems, strategic
research is necessaryto support applied and adaptive studies on the need for water at
different growth stages of the plant. Strategic studies on genotypic differences in plant
water use and water-use-efficiency in production are also needed, and of water use in
mixed-cropping and agroforestry systems.
60
Leaving aside the political and economic problems of extending the presently
irrigated areas - and recognizing that irrigation has been a major factor in increased
production over the past 30 years - the efftciency of use of irrigation water has been
lamentablylow, and poor irrigation practices have often resulted in large-scale salinization.
In some places, salinization has also resulted from changed aquifer flows following
deforestation, and from the recharge of some irrigation aquifers on coastal areas.
Reclamation of saline areas is difficult and expensive,but some use of these areas may be
possible if salt-tolerant plant speciescan be developed, especiallyif their use is combined
wit!] measuresto reduce the salinity level.
Soil yl~ysical cotxliliom The best managersof soil physical conditions for crop
61
production are the soil fauna, which create the pores through which air and water move,
and mould and stabilize the soil ‘aggregates. As organic matter is lost from a soil under
cultivation and the return of organic matter is reduced, soil structure deteriorates, and the
farmer must attempt to improve it by tillage. Some soils have an inherently poor structure,
and are prone to surface crusting and compaction, both of which can be exacerbated by
poor soil management. The structural deterioration not only reduces the amount of water
available for plants, but also increasesrunoff and contributes to the susceptibility. of the
soil to erosion. Although there is a need to gain more understandingof the factors placing
some soils at particular risk, recuperation of the soils is most likely to come from applied
and adaptive research. Mechanical methods of reducing compaction and soil crusting are
22
seldom a viable option to the developing-country farmer, and neither is the addition of soil
improvement agents such as gypsum. Viable answers to ameliorating soil physical conditions have to come from the managementof crops, trees, and ground covers to promote
increasedreturns of organic matter to the soil.
62
Soil biological conditions. Until recently the importance of soil biota to sustained
soil productivity has received little more than lip-service. There is now more general
recognition of the importance of maintaining biodiversity amongst the soil flora and fauna
(Hawksworth, 1991); but much more needs to be done at a strategic level to appreciate
the potential and possibilities of managingcomponentsof the,biological soil population. It
should be a cause of embarrassmentto the scientific community that even now there is
little recognition that lossesof up to 30% of the yield may be occurring in a great many
crop-production systemsdue to the failure to recognize the damage causedby root pests
and diseases- in spite of the availability of simple methods to evaluate the losses - and
such phenomenamay often be a causeof declining yields in high-input systems. There is a
real need for diagnostic research to establish the extent of such problems in tropical
conditions, and the effects of intensified cropping on the problem.
63
Soil er+osio?r.Wind and water erosion are widespread and serious in India (Abrol
and Sehgal, 1994) and elsewhere. They are a major cause of unsustainability, although
often a secondaryrather than a primary cause. The primary causeis often inadequateland
managementpractices. While more strategic researchon factors determining the relative
susceptibility of soils to erosion, and on the environmental factors inducing erosion (such
as rainfall patterns and wind characters) may contribute to a better understanding of the
problem, the need to find farmer-acceptablecontrol and mitigation methods is of primary
importance. Farmer reluctance to adopt vetiver grass as a control measurebecauseof its
unpalatability to stock, and farmer aversionto alley cropping becauseof the costs in labour
and land, are excellent examplesof the need for greater farmer involvement in the research
process. While foresters, agronomists, economists, and soil scientists may collaborate,
their labours may be better directed to achieving the early involvement of farmers themselvesin the design and planning of the research.
64
The scale at which erosion control must be planned is also important, and this
meansthat the community or communities must also be involved. By and large, technical
solutions are available- terracing in the steeplands,strip-cropping and grass barriers, zerotillage and mulching, and agroforestry systems. The most urgent need is to identify
methods acceptableto land users. There is always a cost for erosion control, as for other
factors of sustainability. The critical research need is to identi@ acceptable methods by
which the costs can be met.
The alternative agriculture option
65
Recognition of the importance of organic-matter maintenance,and of the long-term
and off-site effects related to sustainability, has led to renewed interest in so-called
‘alternative agriculture’ methods. Here, maintenanceof soil productivity is sought from the
use of organic material, the maximization of biological nitrogen fixation, and the minimization of nutrient losses - while avoiding the use of inorganic fertilizers and synthetic
pesticides. Wherever such method5 are economic and will lead to the production of
23
sufftcient yields, they constitute a desirable basis for sustainable production systems.
However, certain difficulties have to be recognized. The most serious for soils in the
tropics is that many are of low or very low inherent fertility. Traditiona! methods of
fertility maintenance,which involve the use of trees or animals to allow nutrients to be
concentrated on the cultivated area, are mostly no longer viable becauseof the increased
demands being made on the land. While recycling of all available organic residues is
important, recycling will not raise the productivity of soils of initially low inherent nutritional status. Such soils are unfortunately widespread in tropical regions. Recycling by
itself does not provide an avenue of escape from the poverty trap. Integrated organic/
inorganic managementmethods will most commonly be needed to raise,productivity, and
ensuresustainability.
66
An essentialcomponent of any alternative agricultural strategy must be the maximization of biological nitrogen fixation in the system.Mostly this will be from the inclusion
of legumes- and as noted above there is still an opportunity for major contributions to be
made by strategic research on several aspects of nitrogen fixation, as well as by inputs
from applied and adaptive research.
67
A frequently mentioned obstacle to the practice of returning crop residues to the
soil is the demand for the residues for other uses, such as stock feed, firel, and roofing
material. Solutions to this problem are an important part of research on sustainability. It
may mean that the plant breeder has to redesign the crop plant, or the agronomist has to
find a way to produce the organic material neededto satisfy the plant requirements.
68
Considerableenergy inputs are also often neededto ensure adequate water entry
into the soil, whether by irrigation, water-harvesting techniques,or tillage. The amount of
energy required for soil tillage can often be reduced by increasing the organic-matter
content of the soil, but the advantages to be derived from the mechanization of soil
manipulation methods are often of compelling interest to the farmer who has to do the
work. Tillage is also neededfor seedbedpreparation and weed control. The work at IITA
and elsewhere &al, 1991) has shown that in humid regions minimum and zero-tillage
techniquesoffer considerableadvantagesin terms of energy requirements,but may need to
be combined with herbicide use for weed control.
Thus while organic farming and other alternative agricultural techniques offer
69
significant advantagesin terms of sustainability, in many instances it will be essential to
combine the principles of organic farming with methods to replace nutrients and apply
other forms of inputs to provide yield levels which enable the economic survival of the
farm family.
The envi~onmentaf dimension - sustainability
Even in the developed world, consciousassessmentof environmental costs is only
70
recent, and the inclusion of environmental costs in land management budgets is now
becoming imperative. However, developing policy initiatives to address.the. issue of
internalizing environmental costs is difftcult until productive agriculture is a reality.
24
71
Off-site damageresulting from poor farmland managementhave included additional costs which are not perceived by farmers. By comparison to on-farm losses, this
damage is much greater, and affects a wider range of people. Off-site damage includes
sedimentation of aquatic resources, siltation of reservoirs, and the confounding effect on
the ecosystemas a whole. Finally, the increaseduse of land which agriculture has demanded may damagehabitat and biodiversity.
72
Sustainable use of current agricultural land can reduce environmental off-site
pressures. Coupled with other socioeconomic policy decisions, it can also reduce the
pressureson marginal land or stressedecosystems. Thus the outcome of appropriate soil,
water, and nutrient managementpolicies and a widescale implementation of these policies
will not only enhanceproductivity but also protect the environment.
Apart from the physical availability of land, the desire to maintain an ecosystem
73
balancewill also place pressureson land use. The nonagricultural uses of land, specifically
for forestry and biodiversity reserves,will increasethe pressuresfor increasedproductivity
of currently cultivated land. There are large areas of fragile ecosystems, specifically
steeplandsand wetlands, which demand protection and conservation. Agricultural creep
into marginal areas,especiallyinto steeplandsand swamps,is a major environmental problem in many countries. The urbanization of agricultural land is also becoming a problem in
many developing countries. In almost every country, prime land is already under agriculture, and available land that could be brought under agriculture is usually of inferior quality, requiring high inputs in management. Serious consideration has to be given to competing claims of land use for agriculture and forestry.
74
Problems associatedwith point-source pollution are increasing in many developing
countries. At present, the data is inadequateto make an assessment. However, damage
from mining activities has been reported in many countries (such as Brazil and Malaysia).
Off-site contamination of whole river basinsare often of sufficient concern to warrant the
use of bioremediation and other techniques.
75
Other problems may arise from the impending threat of global climate change Tl:.:
impact of climate changemay be particularly important in areassuch as desert fringes and
savannas,and where population growth is most rapid and the ecosystem most severely
stressed.At the present time, intensification of cultivation is leading to increasing lossesof
soil organic matter, contributing to increasing levels of important greenhousegases,such
as carbon dioxide, methane, and nitrous oxide in the atmosphere. By using agricultural
practices which increaserather than decreasethe organic-matter level in the soil, a win-win
situation can be created, in which soil productivity rises and carbon dioxide is removed
from the atmosphere. It has been calculatedthat an averageincreaseof 0.1 to 0.2% in the
amount of organic matter in the soil would be sufficient to offset the annual additions to
the atmospherefrom fossil-fuel use (La1and Kimble, in press).
The temporal dimension - long-term experiments and modelling
To assessthe relative significanceof factors related to sustainability, it is absolutely
76
essentialto have a seriesof long-term experimentsin different agroecological~zones, some
of which are conducted on a catchmentbasis. Only in this way can organic-matter dyna25
mics and water use and nutrient flow associated with changes in SWNM be studied
experimentally. Catchment experiments are large and costly. The value of a few catchment experimentssupported by relatively simple long-term plot experiments and by simulation modelling (Nye, 1992), will be inestimablein providing a continuing factual basis for
determining productivity changesand the biophysical effects of land-use changes. These
experiments would also provide important international reference sites for studies of
organic-matter dynamics and the releaseand assimilation of greenhousegases. Possibly,
and most importantly, they would provide a reference point where indicators of sustainability could be factually assessed.
77
There is no doubting the power of modelling in association with agricultural research, both for its indication of the probable consequencesof alternative treatments in
various systems,and also for the indication which modelling can give of the most sensitive
parts of a systemwhich may be responsiveto treatment. Other types of models important
in soil resource managementinclude an estimate of the sustainablehuman carrying capacity of a target zone as a fbnction of different levels of inputs. Econometric models, models
predicting the long-term impacts of global climate change on the resource base and resource performance, and models evaluating irrigation practices all have valuable contributions to make - not only to understanding the complex processesinvolved, but also to
research efficiency and cost-effectiveness. However, without an experimental base for
validation their value is limited and may be dangerouslymisleading.
The spatial dimension - location specificity
78
The problems of SWNM differ considerablyin significance and extent in different
parts of the globe. To assesstheir relative significance,it is necessaryto have some means
of categorizing them in relation to major land and land-use characteristics. There is, of
course, much spatial variation. One of the ,great diff&ities in agricultural development
and in the application of researchrelated to SWNM is its location-specificity. Soils are not
only individually complex, but their properties vary considerablyover short distances, and
vary in time as well as in space.This variation requires that managementmethods must be
flexible. Consequentlyland managementmethods also show considerablevariation Management has to respond to climatic differences, soil differences, la& differences, and the
human factors related to land use. Farmers living in close relation to their land are always
aware of this, and adjust their managementaccordingly, recognizing their prime need to
produce sufficient food to survive. A categorization of the problems of SWNM is
therefore not an easytask.
FAO, through its Agroecological Zones (AEZ) project (FAO, 1991), has
79
approachedthe problem of land categorization in terms of climatic suitability. Allying this
with the extensive information from the FAO/UNESCO Soil Map of the World and
national soil surveysgives a biophysicalbasefor further refinement. Satellite data from the
UNEP GRID project provides some indication of current land use and land-use changes,
but little about the factors inducing change,or about soil degradation.
A data base incorporating more information about population, farming systems,
80
and other factors is essentialto a proper analysisof the priorities for SWNh4 research. In
the absenceof an adequatecategorization of the extent of the problems, we have used six
26
ecologically defined regions or ‘target zones’ which give some internal consistency in the
major problems of SWNM as a background to our assessments.They are:
l
the desert fringe;
l
the nonacid savannas;
. the acid savannas;
l
the humid forests;
. the wetiands;
l
the steeplands.
The principal soil and climate characteristicsof each region are given in Annex II.
81
While there is some consistency in the problems within each target area, there are also
considerable variations due to landscape position, soil-type differences, and the past
history of land use. The location-specificity problem can perhaps best be appreciated in
relation to the problems of the Machakos area in Kenya. On the better soils of the area, a
successful land-settlement scheme has been. implemented supporting a relatively high
population density and a farming -systemin which sustainability appears to have been
established(ACIAR, 1992), while in other parts the struggle with the descendingspiral of
unsustainabilitycontinues (Figure I. 1).
The dominant farming systemsin the desert fringe and the nonacid savannasare
82
animal-based,ranging from nomadism to mixed farming with improved pastures. In the
acid savannasand forest areas,the dominant farming systemis shifting cultivation - with
some animalsand grazed fallows in the savannas,and tree-basedsystemsin the forests; the
trees may include somewhich produce a cashcrop. In the wetlands, there are mainly ricebased systems,and in the steeplandsvarious forms of sedentaryagriculture and livestock
production, usually with someform of terracing to control erosion, predominate.
83
Nutrients are liable to depletion everywhere, and are subject to continued removal
by crops. Methods to maintain nutrient levels as cultivation becomes more intense are
critical in almost all areas. Traditional replenishment of nutrient levels is from animal
manure in animal-basedfarming systems, and from nutrients accumulated in the fallow
vegetation which regenerateson cultivated land. The organic matter added in manure or
from fallow vegetation is critically important to the sustainabilityof traditional agricultural
systems. It contributes not only to nutrient levels, but also to water entry and retention,
resistanceto erosion, control of acidity, and biological activity in the soil. Several previous
assessmentsof the soil-, water-, and nutrient-related constraints to crop production have
been made, and references to these constraits are given at the end of this paper. More
details about each target zone and the dominant farming system in the zone are given in
Annexes IV and V.
Problems of water shortage and of methods to improve water collection dominate
s4
in drier areas, and problems of flooding and water excessare of major concern in wetter
areas. Difficulties with water collection and distribution are,exacerbatedon a landscape
scale by sedimentation, mostly arising from erosion in adjacent areas. Water shortage for
both agricultural and horticultural use will be one of the most serious problems of the 21st
century. The use of water for irrigation must not only be made more efftcient, but also
integrated with forestry into national and community planning of development at the
village and catchmentlevels. Problemsof water collection and.distribution must always be
associated with proper planning of drainage to ensure that salinization, flooding, and
27
waterlogging difficulties are precluded. More than ha!f of the areas which are presently
irrigated have been affected by salinization, and every year several million hectares have to
be abandonedbecauseof salinization (Ahmad, 1991). The special problems of irrigated
areasare discussedmore fully in Annex V.
85
There is at present inadequatedata available regarding the extent and numbers of
people involved in each zone, and the extent of different farming systems. Data collected
by the World ResourcesInstitute show that the relative order of size of the target zones
we use is: humid zone > acid savanna> nonacid savanna> wetlands > steeplands> desert
fringe. For population, the order is: humid zone = nonacid savanna> wetlands > desert
fringe > acid savanna> steeplands.
The information and knowledge base
86
Soil, water, and nutrient managementtechnologies only succeedif they are transferred to the farmers. In many countries, the significanceof indigenous knowledge has yet
to be appreciated. Sometimesthe reluctance of farmers to accept technologies may be
related to conflicts with this knowledge. The second kind of knowledge is scientific or
technological knowledge. Transferring germplasm(seed) is easierthan transferring knowledge involving traditions, values,and complexity.
87
The absenceof resource information is a major deterrent to appropriate land-use
policies in most developing countries (Eswaran, 1992). Discriminatory use of land, targeting researchand developmentactivities, and assistingfarmers in the managementof farms
all require information on the soil resources.
The need for a better information base on SWNM was widely recognized in the
responsesto the questionnaire(Annex II). We believe it to be essentialto the better prioritization of SWNM research, as well as essentialto governments endeavouring to improve their managementof natural resources.
88
89
We see a need for high priority to be given to establishinga better data base on
current land use, allied to a geographic information system (GIS), that will enable changes
in land, agricultural, and socioeconomic conditions to be more effectively monitored than
at present. Such a data base would enable apropriate priority for the most serious land
problems facing the national programmes to be identified, and for support to be given to
the programmesaccordingly.
90
Very high priority should also be given to support for an SWNM information network to share information between the national programmes, and to facilitate the sharing
of results between users of land and water and those engaged in research related to land
and water use.
Soil resilience - reversing degradation
Much is known about the causesof soil degradation and the negative impacts of
91
degraded systems. However, information on rates of degradation, a quantified assessment
28
of the state of degradation, and the resilience capacity of the systeni is less.well established, and provides a new avenuefor researchin the quest for sustainability. Resilience
is the ability of the soil or systemto revert to its original or near-original performance level
subsequentto stress (Eswaran, 1994). Soils differ in their rates of degradation under
stressand their resiliencecapability, as illustrated in Figure 111.2.
According to this conceptualization, there is a point of degradation beyond which
92
the process‘is almost irreversible. The patterns of degradation (rate fimctions) and the
ability to revert to the near-original state are criteria which differentiate resistant, resilient,
fragile and marginal soils. The continued application of stressis usually due to cultivation,
since crop and residue removal can move fragile and marginal soils to a point of no return
- although resistant or resilient soils will normally be”ible to return to previous performance conditions.
Resistant soils occupy about 10% of the total global arable land surface, and occur
93
mostly in temperate areas. There are no good estimates of other kinds of soils, and a
reasonableesiimate would suggest that about 50% of soils belong to the resilient type,
about 25% are fragile, and the remaining 15% are marginal. Fragile and marginal soils
occur predominantly in the tropics. Many have reached a state of irreversible degradation
through mismanagement. The downward spiral resulting from increasedpopulations in the
finite land resourcebaseis increasingthe proportion of marginal and fragile soils which are
close to the point of no return, and this is the warning signal highlighted by Agenda 21.
Resistantsoil
STABLE PHASE
Soi! canrecover
underappropriate
nianagcmcnt
Soil cannot
recover
2
3
4
5
6
7
Intensity of degradativeprocess
8
9
10
Figure III.2 Responseof resistant, resilient, fragile, and marginal soils to stress (adapted’fiom’ Lal, Hall,
and Miller, 1989).
29
94
An SWNM strategy must ensure:
l
high productivity from soils in the stable phasewhere degradation is unlikely;
. carefiJ management of resilient soils to avoid degradation or to reverse
degradationwhen it has occurred; and
l
a conservation reserve programme for soils which are irreversibly degraded,
and for fragile and marginal soils which can easily become irreversibly degraded.
95
These are remedial measures,best implemented on a communal basis. An equally
important task is to develop early warning indicators and appropriate monitoring systems
to alert land users of the impending degradation of systems. At a recent workshop on Soil
Resilienceand SustainableLand Use held in Budapest in 1992, the following recommendations (Greenland and Szabolcs,1994) were made:
l
The global data base of human induced soil degradation developed by UNEP, ISSS,
and ISRIC, in collaboration with various countries, should be complemented by a
similar assessmentof:
+ areaswith sustainableland managementsystems;
l
areaswhere degradedlands have beenrehabilitated; and
+ the resilienceof the land resource basein different ecosystems.
l
To implement some of the recommendationsof Agenda 21 in the area of land resource
planning and management, an assessmentof current land use should be made at
national and global levels.
96
97
This will require that:
. existing long-term trend-monitoring programmes, data collection, and experiments are maintainedand documented,and that new ones are supported in key
agroecologicalzonesin developing countries;
l
key species,biotic assemblages,and processescontributing to soil resilienceare
identified;
l
quantitative indicators and threshold values of those attributes which determine
soil resilienceand sustainableland managementare determined; and
. appropriate practices for different soils are identified to ensure land management is conducted on a sustainablebasis.
It was also indicated in the workshop that any researchshould:
be developedin associationwith local communitiesand social scientists;
l
be built on past experience;
. use interdisciplinary teams;
l
be targeted at specific agroecosystems;and
. obtain better information on land-use systems and changes in key soil
properties related to resilience.
l
Biophysicai solutions: the holistic approach
98
Biophysical solutions to most SWNM problems related to crop production exist,
but the challenge facing scientists is to find solutions which are environmentally ,sound,
economically viable, and socially acceptable. Fortunately, there are a number of approaches,some requiring a modicum of fin-ther strategic research, but many requiring only
30
applied and adaptive studieswhich could be integrated with existing production systemsby
joint efforts from farmers and scientists.The need is of course for a whole farm approach,
but as argued previously, the effects of changes also have to be considered on a wider
basis, and on a longer time scale than a single crop season. The effects on successive
crops and associatedanimal systemsalso have to be considered,as well as the relationship
to the landscapeand ecosystem- considerationsusually missing from the farming systems
approach.
99
We are dealing not merely with soil systems, but with soil-water-plant-animalforestry systems. Range managementspecialists,foresters, and hydrologists may need to
be involved as well as soil scientists. The interdisciplinary approach will often need to be
wider than that of soil scientistswith plant breeders and physiologists, and involve ecologists and socioeconomists,and sometimesothers. Not everyone can be involved at every
stage, as teams become unmanageable,but the breadth of expertise needed for sustainability studieshas to be recognized. We have focused on changesat the farm level, for it is
here that most of the decisions affecting resource use are made. It is a challenge to
scientiststo evaluate the various advancesin strategic and applied research - not only at
the farm level but also at the landscapelevel - and to consider a time scale not of a crop
seasonbut of decades.
100 A questionnairewas also sent to those whom we believed had sufftcient specialist
knowledge to make an assessmentof the problems of SWNM (Annex VI). The answers
have been collated to simplify presentation.The important problems of SWNM as seenby
our correspondentsare given in Figure 111.3.
Legend
H Nuttient depletion/deficiency/timing
KBI Soil erosion and degradation
a Socioeconomic (prices, policy, markets)
B Inefficient water use/management
lZ4 Faulty researchsystem/methods
El Unsustainablefarming/conservation
&i Soil acidity
- El Nonadoption by farmers’
R Competing
usesof water
EJ Lack of organic matter
B Inadquate fertilizer use/management
I Compaction
I54Seasonaldrought
1D Water stress/watcrlogging/drainagc
=r---------
----
N = 130
Figure III.3 Perception of major SWNM problems.
31
IV
RESEARCH PRIORITIES
Overview
101 From the issuesraised previously in this paper, it will be apparent that increasesin
global agricultural productive capacity must go hand-in-hand with the conservation of the
resource base, and at the sametime some’provision must be made for other uses of the
land. The downhill spiral of unsustainability,which results from mismanagementand the
fact that many regions of the world are already at the lower end of the spiral, justifies a
senseof urgency. If developing countries are to be helped to meet these challenges,longrange concerns about food security, income generation, and the condition of natural
resources must be addressedin planning future economic and social development. The
supporting researchmust be holistic and integrated, and always have the structure and the
function of the broader agroecosystemin mind, be conducted on a landscape(catchment)
basis. Though researchon soil, water, and nutrient managementis essential to this task,
there needs to be recognition of the fact that there is a cost attached to sustainability - a
cost which farmers must be aware of, which scientists must address, and which society
must be willing to pay for.
102 To reverseor reduce unsustainabilitytrends, omnipresentin most developing countries, every attempt should be made to ensure fullest land-user participation in each phase
of the researchprocess- planning, technology development,and dissemination. The above
analysishas clearly establishedthat the implementation of technology has minimal impact
at the farm level if the social, political, and institutional context of on-farm and off-farm
activities are not considered. It is essentialto capitalize on the opportunities to be reinforced and to identify the constraints which need to be overcome in order to approach
sustainability. Applied soil, water, and nutrient management research that does. not
address issues of gender, social structure, indigenous knowledge, and the functioning of
different local institutions, is unlikely to have permanentapplication.
103
To develop priorities, the following points must be borne in mind:
l
Athough soil-related research has a high element of site-specificity, there are
common threads among the target zones.
l
Any target zone may have many constraints, and it is necessaryto recognize
the relative importance of the individual constraints and their interactions with
other constraints, and then to prioritize researchactivities as a function of the
constraints and objectives.
l
A number of problems have a common cause - for example, depletion of soil
organic matter will seriously affect several soil physical, chemical, and biological properties.
l
There is an urgent need to develop indicators or early warning signs of resource degradation. Causeand effect is generally complex, and may be misleading. A good example is erosion in some environmentswhich may be triggered
by chemical or physical constraintsto vegetation establishment,a lack of which
promotes erosion; addressingerosion is only a partial solution, and the larger
causemust be understood and rectified.
32
.
l
l
l
Though it is easierto resolve componentsof problems, a holistic approach on a
farming system or watershed basis has a longer-term impact with residual
benefits.
Though soils are subject to improvement, the soil-water-plant-animal-humanenvironment linkages are so overriding that if the system is not addressedas a
whole, the solutions may be temporary.
Finally, the key to moving upwards in the sustainability spiral is income
generation, and to a lesser extent reduction of risks. These two issuesare the
prerequisitesfor sustainability.
Setting priorities
104 The rationale for developing priorities in soil, water, and nutrient management
involves many different considerations. For national agricultural research systems
WARS), the considerations include the availability of stress-free land, population
distribution, in-house capability to undertake the task, the availability of fimds, and even
the importance attached to SWNM research by national decision-makers. For resourcepoor farmers, the primary consideration is income generation, with subsidiary considerations of equity. For the international community, the main objective is to enhance the
ability of a finite resource base to-support the burgeoning population. Thus the emphasis
varies with the population under consideration. It is important to establish some kind of
rationale specifically for donor-supported research and to prioritize the activities in a
generic fashion so that donors can select areas depending on their customer requirements
and the global relevance of the problem. We have noted elsewhere the inadequacy of
availabledata basesfor the presentationof the problems.
105 The following are some considerations that have been taken into account in our
assessmentof the relative significanceof the problem areas:
l
the likelihood that the problem will be solved by research,and if solved that the
results of the researchwill be acceptableto the land user and implemented to
bring about the desired change;
l
the relative importance of the problem with respect to attaining sustainable
development;
l
the number of people who will benefit by a resolution of the problem or the
number of people impacted by the problem;
l
the relative magnitude of the gains in production that will result through
resolution of the problem;
l
the significanceof the environmentalimplications of the problem;
l
the gains in production in terms of cost-effectivenessand/or a shorter time
frame from amelioration of the resource base rather than modification of the
plant;
l
the generation of increased labour use and a reduction in the seasonality of
labour use, together with an increasein production;
. increased production, with the capacity to promote small-scale associated
agrobasedindustries;
l
the involvement of institutions currently involved in aspects of basic research
diffusion activities, and their linkage with other more applied research
institutions and NARS to facilitate technology development; and
33
l
the relative magnitude of other benefitsto society.
High-priority
research components
106 On the basis of the discussionsin the preceding sections, and the responsesto the
questionnairethat was distributed (Annex VI), we have integrated the specific problems of
SWNM research into ten principal problems where we believe research has a major
contribution to make. They are, in no particular order:
l
nutrient losses and soil acidity due to the export of nutrients via crop
harvests, leaching, and soil erosion;
l
land degradation and alienation, by erosion, pollution, and urbanization;
l
the low level of application of knowledge already available from research;
l
l
l
the lack of long-term experiments which can be used to monitor changes
in soils due to land-use changes, and as a basis for validating indicators df
sustainability and developing simulation models to predict the effects of
land-use changes;
the distortion of farmers’ decisions on sustainable land management
methods by markets or policy decisions affecting costs and prices;
the impermeabilization and loss of soil structure (architecture) due to
inappropriate land-clearing and cultivation techniques;
.
the loss of soil organic matter by excessivecultivation, and the inadequate
returu of organic materials to the soil;
.
inadequate methods for the diagnosis of SWNM problems;
l
l
inappropriate methods of water management, in both irrigated and
nonirrigated areas; and
The inadequacy of the information base on which decisions about land
use, crop production, and grazing management must he based.
107 All of these problems occur in one or more of the target zones. Their significance
differs between zones. In relation to most of the problems, there is a substantial data base
of information which can be used for adaptive researchon location-specific problems, but
there is also a needfor further strategic and applied research.
108 We have included as a principal problem the lack of an adequate information
base. We believe it to be essentialto the better prioritization of SWNM research, as well
as essential to governments endeavouring to improve their management of natural
resources. In Agenda 21, the inadequate information base on which action has to be
initiated is recognized in the call for “an action programme on land resources planning
34
information and education for agriculture [to] be developed to systematically identify
sustainableland uses, and production systemsfor each land and climate zone, to control
inappropriate land use and to take into account the actual potential carrying capacities,and
limitation of land resources”.
High-priority
research areas
109 Addressing the researchproblems identified becomesan academic or even a futile
exercise if the problem is addressedin isolation, and, not in the context of the. socioeconomic limitations. The driving force in defining the priority areas should be the ability
to move upwards in the unsustainabilityspiral.
110 The researchareasthat should be given priority attention are those where there are
many sites near or at the bottom of the spiral, and those where factor productivity is falling
most rapidly. A rational prioritization of needed research requires information about
where different communities are operating on the spiral of unsustainability. This inform.ation needs to be supported by knowledge about the resilience of the soils on which the
communities depend. Such information has not yet been assembledin usable form, and we
believe that high priority needs to be given to assembling this information. In the
meantime,there are areaswhere acute problems are already apparent, as in mountain areas
and other steeplands,at the desert margins and the drier savannaswhere desertification is
occurring, in irrigation schemeswhere siltation of reservoirs and salinization is reducing
productivity, and in more populous areas, particularly on marginal lands, where shifting
cultivation has been the traditional land managementsystem. Thus we see that priority
should be accorded to:l
land and water management in the mountaiuous areas and steeplauds;
l
land and water management in desert margins;
l
land and water management in irrigated areas;
.
management of acid soils;
l
factor productivity in wetlands;
.
integrated inorganic/organic farming methods for savannas;
.
alternatives to shifting cultivation for humid forests.
111 All of these are under study or under consideration for development as major
projects. There are also many activities which do not form a part of current projects
related to these priority areas,but are very relevant to them. These include many activities
managed by NARS, many research projects based in developed countries, such as the
USAID4mded Soils CRSP and the soils projects of ORSTOh. ,There are also many
development projects conducted by NGOs, in which there is a major component of
adaptive research, but which have only weak linkages with organizations conducting the
strategic and applied researchon which the adaptive work is based.
35
112 We agree with the views expressed most clearly in .the responses to the
questionnaire(Figure IV. 1) that the most urgent need is for adaptive researchto apply and
adapt what is already known to specific situations.
113 We believe a mistake of the past has been to see strategic and applied researchas
the starting point, producing new knowledge which users are expected to evaluate. A
harmonious partnership needsto be established,in which the starting point is the problem
as it exists in the field, and the highest priority is given to finding a solution. Resolution of
the problems may require strategic and applied research. However, most farmers are
already finding their own solutions by trial and error. They need to be brought into a
system in which adaptive research to solve their problems is conducted, and linked to
centreswith the necessarystrengthsin applied and strategic research.
Thus we believe very high priority must be given to creating a mechanism- rather
than a structure or strategy - for SWNM that *will facihtate the interactions between the
many participants. The mechanismhas to enablereal linkages between those involved in
all aspectsof relevant research to be formed and maintained, with a flow of information
from the adaptive to the applied and strategicwork, and equally in the other direction.
114
1
W Adaptive on-farm research for SWNM
rq! Integrated plant nutrition (organic-inorganic)
KLl Socioeconomic research (inc. indigenousknowle&
20
3 Soil and water mazagemcnt
KB Minimum data sets (overlav AEZ/GIS. etc.1
3 Efficient nutrient uptake
Ea Organic-matter research
Soilcompactionlphysical structure
Am
Root/&osphere
N= IO9
Figure IV. 1 Perceptions of major research
priorities.
115
The biophysical problems of SWNM may be of dominant importance to any one of
There will be an advantagein concentrating
strategic research efforts in one or in relatively few centres, if the mechanismexists to
ensure that all can benefit from the results.
the target zones, but several are also generic.
36
V
HARMONIZING ACTIVITIES - AND A SUGGESTION FOR
IMPLEMENTATION
The need for harmonization
116 It would seem particularly important to harmonize thk activities of the different
organizations involved in tackling the problems of SWNM research to ensure the most
efficient use of resources. The growing awarenessamong the donor community of the
significance of SWNM research, and the fact that national programmes need support for
their applied and adaptive research, as well as strategic research, has led to the establishment of severalinternational initiatives in addition to those of the CG system, such as
IFDC, IBSRAM, JCIMOD, and TSBF, each of which was establishedto provide essential
support to national SWNM-related activities. As a result, there is now a considerablebut
fragmented and poorly coordinated international programme of activities on SWNM
research.
117 When discussingthe expansion of the CGIAR system and the establishmentof a
number of centres with ecoregional mandates,TAC (199la) suggestedthat “there could
be a series of agroecologically focused institutes or ecoregional mechanismslinked by a
global council”. We certainly see a need for better linkages between the many organizations now involved, but believe that this might best be achieved by establishing some
form of ‘clearing house’which would be responsiblefor facilitating and catalyzing information exchangebetween consortia working on priority problem areas, and harmonizing the
activities of the wide range of other organizationsinvolved in related SWNM research.
118 One area in which we see the need for better linkages to be particularly important
is in relation to assistingvarious international organizationsin coordinating their relations
with different NARS. In this respect we believe the views and interests of the NARS must
be paramount.
Assessing comparative advantages
119 The principal international organizations involved in SWNM research are listed in
Table V.l. While the activities of the UN organizations have been given little specific
attention in earlier sections, their vitally important work in supporting NARS - in the
development of the World Soil Map, and in establishingglobal monitoring systemsof land
use and other factors related to environmental change - is fblly recognized. All national
governments are also involved in SWNM. Normally several government departments
undertake related aspectsof researchand other activities involving SWNM. Universities,
NGOs, and others are also involved. The important contribution made by research
organizations in developed countries to SWNM researchin developing countries has also
to be recognized. These national and nongovernmentalorganizationsare too numerous to
list here. NGOs are gaining much experiencein handling location-specific problems, but
the full value of their success&l projects is often not obtained because there is no
mechanismfor linking their work to that of others. Each &fhe different organizations is
playing an important role in SWNM research. A discussion of their ‘comparative
advantage’in basic, strategic, applied, and adaptive researchis given in Annex VII.
37
.
120 Following the TAO recognition of the increased importance to be given to
problems relating to resource management,several of the CGIAR IARCs were ‘asked to
assume ‘ecoregional mandates’(TAC, 1991a.) In the paper addressing this issue, TAC
states: “The ecoregional entities will take primary responsibility for the bulk of the CGIAR
research on resource conservation and management,which is absolutely critical to the
sustainability of production systems. The primary focus will be on strategic research,but a
key question for the CGIAR is the portion of the adaptive, applied, and strategic research
for which an international systemhas comparativeadvantage.“
121 We seethe last statementas a key question, although not for the CGIAR alone. It
is also important for all of the international organizations involved in SWNM. In a paper
issued shortly after that which addressedthe ecoregional focus, TAC (1991b) considered
the relations between the CGIAR centres and the national agricultural research systems
(NARS). They rightly state that: “Another problem is the need to avoid placing too great a
burden on national systemsthrough independentapproachesmade to the same institution
by several centres.” The problem involves not only the CG centres but also most of the
other organizations listed in Table V. 1 that are likely to be approaching the same national
organizationsto invite them to participate in their activities.
Table V. 1 Some organizations involved in SWNM activities.
CG IARCs
Other IARCs
NARS in developing and
developedcountries
UN agencies
Others
CIAT
CIFOR
CIMMYT
CIP
ICARDA
ICRAF
ICRISAT
1FPR.I
IIMl
IITA
ILCA
1RRI
ISNAR
WARDA
IBSRAM
IFDC
ICIMOD
ISluC
CAB1
AVRDC
Including government
organizations concerned
with agriculture, forestry
irrigation, environmnt
natural resources,
land development, land reform,
land consemalion, and
researchin the above areas,
universities, NGO’s
FAO
UIVEP
UNESCO
IAEA
WMO
WI-IO
ISSS/CIP
IGBFYGCTE
IUCN
TSBF
WRl
NGO’s
The TAC suggestedthat a way forward for the NARS and CG centres would be by
I22
networking arrangements, and indicated that the networks formed might involve some
organizations other than the NARS and CG centres. We agree that some form of
networking arrangements are needed. To avoid a ‘top-down’ approach to network
management, the route taken by IRRI, in which its networks were redeveloped as
‘consortia’, has advantages. In a consortium (defined by IRRI as “a limited number of
national and international institutions formally organized to collaborate in research,
training, and technology generation designed to meet mutually agreed objectives”) the
partners are expected to play equal roles. It may remain desirablefor the managementof a
consortium to be with an international body seen to be independent of the interests of any
one country, or as having an interest in extenc!ing the results of any one research
organization.
123 The comment of TAC on this problem was (TAC 1991b): “As far as cooperative
networks are concerned, if they are to be successfL1and sustainable there is no viable
alternative to a demand-driven system in which the countries themselves define the
problems and determine the priorities.” We would agree with this statement provided that
“countries” allow the voice of the farmers and other users to be heard, and that a
mechanismis in place to facilitate the sharing of results and information. We see that an
equal partnership needs to be establishedin consortia in which all -those with relevant
interests and expertise are involved. We also believe that an international organization has
a considerablecomparative advantagein the managementof a consortium provided that it
is not generating results which the partners in the consortium are expected to embrace.
124 International centres are seen by many NARS as models for the research process.
Divorcing the IARCs from adaptive research,where we seethe most immediate needs for
SWNM research,is likely to lead to neglect of adaptive research by the NARS. Thus we
believe that an international effort focused on the methodologies of adaptive research is
essential. An international body independent of particular interests should be most influential in promoting the sharing of results and information.
A suggested mechanism for SVWN research
125 At present there is no global strategy for research on the problems of sustainable
land management,or on the major components of land management,namely soil, water,
and nutrient management.There are many organizations concernedwith various aspectsof
sustainableland management. Many of theseattempt to deal with local problems where an
immediate answer is needed, as in the control of soil erosion on an economic basis or in
the rights to land tenure. Others contribute to the already substantial knowledge of soil
characteristics and behaviour, and the factors determining soil productivity. Most internationally supported research has been directed to problems of yield improvement on a
plot basisrather than a catchmentbasis. Concern is sometimesexpressedthat the focus on
yield draws attention away from the problems of long-term sustainability and the need to
address production and sustainability problems on the basis of the whole catchment or a
larger area.
126 For developing countries, and particularly the poorer of them, only through greater
productivity can the threat of environmental damage be reduced - by giving attention to
reducing the pressure on marginal lands, and by taking the necessarymeasuresto avoid
environmental damage. There is no conflict between measuresto increase productivity
and yield and measuresto improve the quality of the environment and conserve natural
resources.There is rather a considerabledegree of complementarity between them. There
are varieties of most crops available with yield potential greatly in excessof current yield
levels. The potential of these improved varieties will not be realized without improvements in SWNM. The long-term sustainability of cropping systemsand the avoidance of
environmental degradation are also dependent on the development of better methods of
land management. Many of the problems need to be solved in the immediate future if
39
irreversible damage to the productive capacity of the land, the availability of water
supplies, and the quality of the environment is not to occur.
127 We know how to make most soils yield more than they do at present. What we do
not know is whether the changesneededto make them more productive are sustainablein
all instances, nor how to make changeswhich are adapted to the social, economic, and
political conditions in which most of the land threatened by unsustainability is used. Nor
do we have sufficient information to know how important the off-site effects of land-use
changesare.
128 The organizations neededto conduct the necessaryresearchalready exist. But the
research is too fragmented, with inadequatefocus on major problems; there is too little
coordination of the work between the different international organizations, between the
international and national organizations, and between governmental and nongovernmental
organizations. Too little account is taken of indigenous knowledge, and socioeconomic
problems. Within some national and international organizations there is too little interaction between crop and soil scientists, between the agriculturists and the foresters, and
between the biophysical scientistsand the socioeconomists.
129 To managethe activities related to specific SWNM research problems, we suggest
that research consortia (or some formalized linkages) be formed, some of which might
evolve from existing research networks. The consortia would need to be focused on the
priority research areas identified previously, and would need to be representative of the
range of disciplines that need to be involved and of the national and international organizations with a significant interest and expertiserelated to the problem.
130 The consortia would have responsibilities to ensure that not only an effectively
coordinated, demand driven, user-based, interdisciplinary research programme is developed, but that an appropriate training programme is also implemented. To support the
work of the consortia we suggestthat an information system,including a GIS data base on
land use and land-use changesbe established,and an information network created. For the
NARS we would seean advantagein that linkageswould be to the consortia rather than to
competing international centreswith related interests.
131 To harmonize the work of the consortia, and to serve as an information centre fol
the consortia and governmental and nongovernmental organizations conducting development projects attempting to establish productive and sustainable land management systems, we suggest that what, for want of a better name, we have termed a ‘clearing house’
should be established.
132 The ‘clearing house’ should provide the necessary mechanisms by which the
involvement of scientists, policy-makers, and farmers in the consortia and in its own
operations are ensured, and appropriate leadership provided for the consortia in their
activities in technology generation and adoption.
133 The first challenge is to link and harmonize the presently fragmented research
efforts, so that:
l
results and problems can be shared;
l
duplication, which is expensive,is reduced;
l
l
.
priority-setting is organized;
researchrelevanceis established;and
accountability is promoted.
/
134 Finally, it is reemphasizedthat technical researchand developmentalefforts in soil,
water, and nutrient managementwill only have long-lasting impact if:
l
l
l
.
l
.
local community control of resourcesand environment is promoted;
income generation and reduction of risk is encouraged;
intergenerationalequity is sought;
national policies do not conflict with sustainabilityefforts;
the land-user has an integral role in the researchand development effort; and
appropriate attention is given to spatial and temporal issues.
“We have now rhe rechnical capabilify 10 build eudwin~grmalionuituld global mrfrifiorl
security systems based 017sound principles where the short and long-term goals of
developmentare in harmony wiih each other. What we often lack is the requisite blend of
polirical will, professiorral skill, and farmers’ participatiorl. We live in this world as
guests of green plants and of the farmers who cultivate them. If farmers are heiped to
produce more, agicrrltwe will 31of go wrong. If agriculture goes righf, everythiirg else
will have a chancefor success.I’ (Swaminathan, 1986)
41
Annex I
The symptoms of unsustainabiiity
Yields changes. Globally, yields of the major cereals have been increasing on a per hectare basis for the
past 50 years, and continue to increase (Figure Al.l.) Yields are still well below established maxima so
that there should be scope for further, and in most casessubstantial, increases. Why then the concern?
The first problem relates to the return per unit of input, where areas of intensive rice monoculture and
high yield levels, stagnant yields, and declining trends in factor productivities are now observed (Pingali
and Rosegrant, 1993.) The secondproblem relates to areas where low or zero inputs are used, as in many
parts of Africa, where sorghum. millet, and cassavayields have been declining or static at very low levels
for two or three decades(Table Al. 1). The reason for falling per hectare yields is declining soil fertility,
associated with more frequent land cultivation and the need to cultivate marginal land which was
previously considered to be unsuitable.
Yields and world food supply
(b)
4 ;. A Wheat
-4
a
0 rice
"maize
3-
-3
52
z 2cd
3
.
A/-=-- A-%5
A/
A/
1 . */$l-n,o-
. 7
2
-2:
‘;3
.e
- *
,0.00--m)
OY&JHOo/n- o-m3
-1
t
1940
1960
.
1980
9
1940
.YEK
1960
,
I lo
1980
.
Figye A I.1 Trends in total area (a) and averageworld yield (b) of the three major cereals(data from FAO
Pmlnctiw~ Fccntmd-.r, collatedby Evans,1983).
Declining quantity and quality of land resources. The effects of increasing population pressure on land
resourcesare illustrated by the data (Figure A1.2), which show that land for further development will have
almost disappeared by the year 2025, escept for a few countries in Africa and Latin America. Future
development must depend on increased productivity and intensified land use. Only &out 11% of arable
land is resistant to degradation, or strongly resilient (Figure 111.2). All of this land is currently intensively
cultivated. Other soils are being degraded. They differ greatly in their ability to recover from stress, but
most soils have the ability to recover if the stressis not extreme. Fragile and marginal soils degrade easily
and have limited resilience.
43
TableA I. 1 Meanannualyieldsandproductionof somemajor staple:;.
(a) Sonlecountrieswith decliningor stagnatingyields,
(b) Sonlecountrieswith increasingyields(datafrom FAO productionyearbooks)
Crop
coumy
Yield (kg ha-l)
61165 69l71 79181 8919I
(a) Stagnating and declining yields
Bangladesh
wheat
Kenya
Production(WO 1)
69/71 79181 89191
854
1678
1869
2011
1665
1747
103
223
803
212
972
210
Rice
Pakistan
Chtedlvoire
2246
1168
2465
1171
2309
1174
3431
335
4884
448
4862
661
Maize
Aqola
C&e dlvoire
Mozambique
Iiaiti
864
773
1003
1058
506
684
569
868
301
728
367
807
467
257
364
245
303
352
383
179
228
497
370
168
Millet
Niger
Sll&ll
422
567
435
397
383
166
975
423
1311
436
1422
185
Sor$uni
Niger
Sudan
445
808
422
744
280
534
262
1525
347
2273
423
2085
6383
6795
6721
6901
6609
7562
10752
Rootsand tubers Gbnna
Zaire
crop
c0uI1lIy
(b) Increasing yields
what
Pakistan
China
Rice
Baqladesb
Indonesia
China
Korea,Rep.
7100
12100
Yield (ko ha-t)
69l-71 79181 89191
3183 5159
13595 18528
Production(WO 1)
69l71 79181 89191
1110
1168
1567
2047
1844 6796
3129 29687
10760 14433
59196 94682
1681
2346
3295
4628
1952
3262
4244
5513
2393 16540 20215 26935
4298 19136 29570 44864
.5622 109853 145665 187036
6282 5574 6780 7770
Apart from the pressuresfor more land for cultivalion, the need for more land for nonagricultural uses is
increasing - for forestv, biodiversity rcsenres,and for urban dcvclopment, which is mostly on areas of the
best land where centres of population have developed. Also large arcas of steeplands and wetlands
demand prelection and conservalion.
The relatively poor qualily of many soils in the tropics has received much attention. While many of the
myths about the difficulties of cultivating soils in the tropics have now been esploded (Sanchez aud Lal,
1992), there is no doubt about their greater fragility and susceptibility to degradation, often due as much to
the higher temperatures and more intensive rainfall to which most are subject as to inherent soil
limitations.
(a) Per caput cropland in year 1990 and 2025
AFRICA
25
3 20
‘E
2 15
00
$110
5
0
0
0.2
0.4
0.6
0.8 -
I
1.2
(haj
,Per caput ttipiand
Source: WRI (1992)
(b) Per caput cropland in year 1990 and 2025
ASIA
25
0
0
0.2
0.4
0.6
0.8
I
1.2
Per caput cropland (ha)
Source: WRI (1992)
(c) Per cnput croplmd in year 1990 and 2025
CENTRAL AND SOUTH AMERICA
2
0
0
0.2
0.4
0.6
I.
r.
u.u
Per caput cropland (ha)
Source: WRI (1992)
Figure AI.2 Predicted reductions of per rapt cropland, 1990-2025.
45
.
I
.
,.
1.~
Subsistencefarmers have of course been ingenious in finding ways to manage soils. This has usually
meant that they have had to find new land to cultivate or new sourcesof organic manures. An active trade
in animal manure has been a feature of the Kano market in Nigeria for many years, enabling farms in a
large area around Kano to be cultivated continuously and productively. In Nepal, farmers have carried
branches from the forest areas to their cultivated plots to use as mulch or for cornposting, a practice which
has enabled them to manage steeply sloping lands on a sustainablebasis for centuries. This system is now
breaking down, as the damage to the forest causes erosion of the watersheds, and as the distances the
women have to walk to find suitable trees as a sourceof their mulch and compost continues to increase.
.
Better ways to manage production from such areas have to be found. There has, of course, been
considerable research conducted to find ways to increase and sustain yields while avoiding soil and other
environmental degradation. These studies have established that the most important factor is proper
nutrient management, but physical and biological factors are also involved. The problems of soil and
environmental degradation are usually due to a combination of factors, and their effects may be both onsite and off-site. Soil erosion is generally considered to be the most common cause of land degradation
(Oldernan er al., 1990) It usually leads to slowly declining yields and reduced productive potential of the
cultivated land, while causing equally insidious and sometimes more devastating effects off-site. Both
farmer and researcher seeking ways to make farming systemsmore productive and sustainable must focus
on the problems of maintaining organic-matter levels. The problems are currently dominated by social
and economic issues, connected with the direct and indirect costs of finding or growing the organic
material, and incorporating it in the cultivated area.
Declining water resources. Water, like land, is becoming a scarce resource. Over the past three decades
30 to 40% of the food supplies of the world have been grown under irrigation, and 50 to 60% of the extra
food produced in the period between 1960 and 1980 was produced from irrigated land. Unfortunately the
rapid espansion of the irrigated areas that occurred in that period is not continuing, and the demands on
esisting supplies for urban and rural drinking water, sanitation, and health are competing increasingly
with the needs for irrigation. It is becoming more and more difftcult to identify new opportunilies 10
develop water-storage facilities. The construction of large dams is now generally recognized as
uneconomic when based on g realistic estimate of the costs, which include the need for erosion control in
the catchment area and drainage facilities in the command area. Opportunities lo develop waterhanfesting methods and to develop microcatchment storage systemsappear to merit much mom attention
than they have so far received. However, for crop production the most important problem is to improve
water-use efficiency. This requires efficiency in the supply of water to the field, and efficiency in the use
of water by the crop to increase economic yield. Many irrigation systems are known to be functioning at
very low efficiencies. The espected life of many irrigation systemshas also had to be drastically reduced
becauseof soil erosion problems in the catchment area of the reservoir, causing excessively rapid sihion
(Shahin, 1993, and Table A1.2).
TableAl .2 Siltation of r~rvoirs in lndia (NarayaxxiandRamBabu, 1983)
Reservoir
Hinkud
Tungabhadra
Mahi
RanaPratap
Nizxnnagar
PO118
Pamchet
Tawa
Kaulagarh
M~yxrahhi
Catclunentarea
1000kllltn’
83
26
25
23
19
13
IO
6
2
2
Sedin~cntation
nitt:
ha In/l
00 kd
Predicted
Obstxvd
2.5
3.6
6.6
9.0
S.3
6.4
17.3
-1.3
1.3
3.6
0.3
4.3
2.5
3.6
4.3
3.6 ‘”
10.1
8.1
18.3
2o.v
A further problem of major significance in the drier irrigated areas is salinity, caused by rising waler
tables in the command area, and in all areas waterlogging. Widely diffcrenl estimates of the extent and
rate of increase in saline areas have been made, but there can be no doubt of Ihc imporlancc of the
problem.
Water quality problems have also been stated to be a concern. The problem is probably greatest in relation
to disease organisms associated with water supplies (Obeng, 1992), although vigilance is certainly
necessaryin relation to chemical contamination. However, in most developing countries where a food
problem exists, the dangers to health are more likely to arise from malnutrition than from chemical
contamination of water. Water quality in relation to potential use for agricultural purposes has received
wide study. With improved irrigation methods, opportunities lo use waler of relatively high salt content
are increasing. India for instance is currently using large volumes of poorquality water for summer
irrigation in areas where the winter monsoon will wash out accumulated salt.
Declining soil nutrient I-c~crw.s. Soils of the tropics present special nulricnt management problems. Not
only are the majority inherently low in nutrient content, but the dominance of low-activity clays mkans
that nutrient retention is poor, and ohen primarily dependent on organic-matter content. In addition,
many of the soils in areaswhich have been cultivated for long periods have been mined of their nutrients.
Recent studies of nutrient balances on a country scale have shown that nutrient mining in sub-Saharan
Africa is widespread (Figure III. 1, and Stoowogel and Smaling, 1990.) Productivity is low because there
are insuflicient nutrients to support economic yields of crops. Once nutrients have been taken from a soil,
recycling of residuescan do little to help, as it will only recycle poverty.
To raise productivity and stop further degradation it is essential lhat nutrients are brought to cultivated
arcas from outside. Where land is plentiful it is possible to do this by lransfcr of nutrients in manure or
tree prunings. Once land availability is restricted, it has to be done by bringing in inorganic iixlilizcrs.
For this to be possible, it is necessaryfor them to be availhble at economic prices. Hence much effort has
gone into the identification of cheap sourcesof fertilizer for the tropics and improvement of the eflicicncy
of fertilizer use. Such work remains essential.
Nitrogen is a special case. It is the only major nutrient that can bc fised from the air. Many studies have
been devoted to methods to masimize the recovery of nitrogen from the air by biological nitrogen lisation
in l’hrming systems of the tropics. Finding better methods to esploit the potential of biolqgical nitrogen
fisation will remain an important research priority for many years to come. In many of the areas where
nutrient availability is a serious constraint to crop production, fertilizers ate not readily available - and
when they are, the costs are greater than the value of the extra yield produced. Hence the problem of
establishing a productive, sustainable system dependson factors beyond the farm gate. Most important is
the need LOidentify and develop cheaper sourcesof organic manures and plant nutrients, preferably those
which are locally available.
The fmner-back-to-farmer
approach
Figutc II.2 ilhatrales the farmer-back-to-firmer paradigm as one model for an integrated approach to
applied and adaptive SWNM research (Rhoades and Booth, 1982). The research process begins with a
joint participatory diagnosis of lhe problem (farmers and scientists may not see the same problem.)
In&cad of scicnlists defining the problem and gcncraling technologies as a rcsull of srratcgic and applied
research in laboratories and espcrimcnt stalions, the research
process
begins with the Brmcr. Traditional
and local knowledge (ethnoscicnce) is given ils rightful place in the research dcsign‘and diagnosis stages.
(Although now regarded as a new approach, it is worth noting that the fertilizer industry was established
47
on the basis of the shared knowledge of a farmer [John Gilbcn Lawes] working with a chemist [Hemy
Gilbert] at Rothamsted manor in England in the last centmy).
In the diagnosis stage three genenl questions have to be asked:
We need an understanding of how and why resourcessuch as manure, crop residues, and trees are
1.
utilized before recommending any changes. What resourcesare available, what are the allernative uses,
what are the alternative values? This information must be matched with the information the scientist has
on the value of resources in terms of their potential contribution to the livelihood of the farmer and the
farm family, the alternative values of the resources(e.g., the nutritive value of crop residues as livestock
feeds), and the environmental and long-term consequencesof one sort of action or another. Decisions may
also be influenced by family and social obligations, which in turn may depend upon the economic status or
gender of the farmer.
Why are these practices followed? Too ohen too much effort has been expended attacking the
2.
‘problems’ without first having understood why they dexelop. Perhaps a seemingly negative practice has to
do with differences in accessto resources, social status, land tenure, or poverty. In the case of gender,
women normally have access to fewer resources than men becausethey lack the necessary labour, have
many household responsibilities, or are escluded from credit. While recognizing that the nature and risk
of soil degradation will be determined by biophysical conditions, decisions as to what the land is used for,
how it is used, and what practices will be followed will be determined by the socioeconomic circumstances.
How do farmers perceive their problems, and how do their perceptions differ from those of
3.
SWNM scientists? The major factors which influence the decision-making of a household are their
livelihood objectives, and their perception of their physical environment and the options for change open
to them. Farmers’ knowledge and perceptions of soil constraints, and their broader production objectives
and ideas concerning production potential and limitations, together with environmental, cultural, and
economic considerations are all used in making decisions on a particular farming practice. The degrading
effects of a particular practice may not in fact be perceived by the farmer (Swift ef al., 1994.)
The farmer-back-to-farmer diagnosis method proceeds through successivephases to define the problem
more clearly and lo seek potential solutions. Each step involves farmer and scientist, culminating in the
on-farm evaluation and testing of the supposedly improved technology. The process should gruitlly
enhance the chances of success. The model provides practical targets that translate. research results into
adoptable land-use practices. It also provides an interdisciplinary forum in which the different perceptions
and aspirations of policy-maker, land user, and scientist‘can be reconciled.
By changing the role of the scientist and extension agent from one where he or she brings precepts,
messages,and packages to the farmer, to one where each brings principles, methods, and baskets of
choices, diffusion of the results of the researchare greatly simplified. The farmer is now part-owner of the
research,and he becomesthe extension agent. And what is diffixing becomesprinciples. concepts, skills,
forms of organization. and ways of experimenting.
Annex III
Biophysical problems of SWNM research
As in any dynamic sysiem. the topics treated below are interrelated. For esample, poor plant growth due
to nutrient delicicncy will have important consequencesfor ground cover and erosion control, for soil
organic matter, nutrient and water relations, for soil physical factors alXcting.succccding, crops,.and for
the impact of root diseases. Research needs in the target zo:xs identified by Sanchez and Nicholaidcs
(1981) are in Table A3.1.
Table A3.1 Priority rankings of rescnrch components by agroecological zones: 0 = none, I = iow, 22 = mediunl, 3 =
high (Sanci~czand Nicholaides, 1981).
Research and develop~nentconqouents
Humid
tropics
Semiarid
Acid
Wellan&
tropics savannas
Sleeplands
A. RESOURCE APPRAISAL.
1. Soil characterization and classification
2. Soil classification for plant nutrition
3. Soil fertility evaluation
4. Fertilizer nxuketing, distribution and use
5. Fertilizer mannfacturino, technology
3
3
3
2
2
3
3
3
2
1
3
3
3
2
2
3
3
2
2
2
3
3
3
2
1
B. STRESS FACTORS
1. Selection of gennplasxntolerant to soil stress
2. Management of soil acidity
3. Salinity
3
3
0
2
1
2
3
3
0
3
0
2
2
1
0
C. NUTRITIONAL CONSTRAINTS
1. Nitrogen fertilizer efiicicncy
2. Pl~ospl~orusfertilizer management
3. Nutrient balance
4. Sulplw
5. Micronutrients
3
3
2
2
2
1
1
1
1
1
2
3
2
3
3
3
0
1
2
2
I
2
1
2
2
D. BIOLOGICAL CONSTRAINTS
1. Biological nitrogen fisation (BNF)
2. Organic residue utiliztion
3. Pjlotosytlthetic efiiciency
4. Rhizosphere efliects
5. Basic stress physiology and genetics
3
2
1
I
1
3
2
1
1
1
3
1
1
1
1
3
1
1
1
1
3
2
1
0
0
I
2
2
3
3
3
3
1
2
2
1
I
0
0
0
0
3
3
2
3
F. IMPROVED FARMING SYSTEMS
I. Sustained production in Osisols/Ultisols
3
2. Multiple cropping
2
3. Agroforestq
3
4. Intensive fertilization of high value crops
0
5. Management of irrigated fanning systems in arid areas0
6. Low input fanning systems
3
0
2
3
0
I
3
3
1
1
0
0
3
0
1
0
0
0
3
0
3
3
0
I
3
G. TECHNOLOGY TRANSFER
1. Validation and adaptation of research results
2. Training
3. Developing fcrtilizcr recomniendations
4. btfonnation scrviccs
3
3
2
3
3
3
3
3
3
2
2
3
3
3
2
3
E. PHYSICAL SOIL CONSTRAJNTS
1. Water management in rainfed system
2. Erosion prevention and control
3. Mechanical inqxdances
4. Larldclearingnletltods
3
3
3
3
49
Nutrient deficiencies. The problem of restoring nutrients lost by harvests or erosion is low to do it
economically. Despite the considerable work by groups such as FAO and IFDC, there is further scope in a
GIS framework embracing soil type and climatic factors to identify the responsivenessof various crops lo
fertilizers, and particularly 10 enhance fertilizer-use elliciency by studies on application placement and
timing. Some developing countries have appreciable deposits of rock phosphates, and it is desirable that
the usefulnessof these to plant speciesbe further studied. In a farming-system conte.Q,the residual values
of applied fertilizer in a cropping sequence,and nutrient losses (including micronutrient losses), from a
site by harvest removal, leaching, and denitrification need lo be identified. These are important adaptive
researchareas.
Recent strategic research approaches which hold great promise for increasing the efficiency of applied
fertilizer are: (i) an improvement of seasonalweather forecasting integrated into decision-making on the
likely return from fertilizing, and (ii) the selection/breeding of genotypesfor high efficiency in the uptake
and use of soil nutrients and applied fertilizer. There are an increasing number of instances of 50-200%
differences between genotypes within species of grain crops, and between tree species, in response lo
added fertilizer. Such a low-input technology should be easy to integrate into many e.sisting farming
systems: additional studies on root biology and nutrient uptake, together with heritability studies on root
characteristics (there is often medium to high heritability), and on nutrilionai physiology would also be
useful.
Biological nitrogen fixation One major area almost certain to enhance productivity with low input and
high acceptability is the enhancement of biological nitrogen fixation by legumes and some nonlegumes.
Restoring soil nitrogen is a major priority - not only to sustainedproductivity but also in the rehabilitation
of eroded aud damaged soils such as mining sites. In a great many, if not most, systems biological
nitrogen fisation is not being optimized. In many cases inoculation with selected bacteria is no1 being
used, and in other cases responsesto inoculation are often disappointing, due either to poor inoculum
quality or to competition from less-effective indigenous strains.
Applied research needs include the development of an inoculum with extended longevity under local
storage conditions in developing countries (and an improvement in the logistics of inoculum supply) and
the selection of bacterial strains which are not only effective but also can compete successfully with
indigenous strains and survive and spread. Important areas of strategic research include the selection ol
genotypes of grain legumes and of nitrogen-fising trees for high nitrogen Iisation (up to fourfold
differences have been recorded) and optimization of nitrogen fisation by tree species used in agroforestry
by genotype selection and appropriate management.
Nitrogen fisation by the dzolfn/;llnabaenn symbiosis in wetland rice is frequently limited by low
phosphate, high temperatures, and insect attack. Amelioration of these constraints by hybridization and
by gene transfer is showing some success.
There is a good case for strategic studies on nitrogen fisation. Above all, there is a need for adaptive
research evaluating the benefit of increased nitrogen fisalion on the growth of succeeding crops and on
soil organic matter.
The increase of nutrient uptake by the management of mycorrhiz needs further study: soils/plants likely
to be responsive-need to bc defined, and methods riced lo bc dcviscd for introducing effective strains
(where they do not already esisl) and for managing their population and spread.
Soil phpicai constraints. Many soils suffer from physical constraints. Highly compacted subsoils
(occurring naturally or by poor management of stock and machinery), surface crusting, and loss of
structure associated with loss of organic malter can induce these constraints. Compaction decreasesroot
penetration and access to water. and surface crusting increases runoff and erosion and decreases fhe
emergence of seedlings. The absence of subsoil root penetration is part of the problem, and soil
compaction is often a major limitation in rehabilitating tin-mine sites Crust formation is particularly
serious in parts of West Africa and India.
There is certainly more work neededon characterizing soils at risk from such factors, and for managcmcnt
practices inducing/ameliorating them. However, costs of amelioration of delelerious physical conditions,
e.g. by deep ripping (impedance) or lillage (crusting) are us~111~prohibitive in developing countries. A
key factor in reducing compaction and surface crusting is tile management of soil organic matter (see
below), which is of great importance in restoring soil structure and water hamesting. In solonized soils,
the grouch of Kallar grass and some tree speciesoften increasessubsoil permeability.
Soil water management. Management of soil water and of nutrition are the two major factors in
sustained productivity. Water is inextricably involved in many phenomena, e.g. nutrient uptake and soil
erosion, Some 28% of arable land has drought as the major constraint lo production (World Bank, 1990)
and periodic water deficiency probably affects as much again. Ensuring adequate rainfall harvesting is a
first requisite, and this is closely related to soil structure and affected by soil organic matter and by tillage
methods. Rainfall-harvesting efficiency can also be enhancedphysically by leading waler into depressions
around trees and along planting rows.
Management of the plant factor holds great hope for increasing r water-use .efIiciency: the
selection/breeding of genotypes with deep rooting systems, the possible breeding of genotypes which are
conservative of soil water early in the season,‘the selection of short-seasongcnotypcs, and (more recently)
the selection of genotypes with high physiological efficiency in water use. Management of the temporal
and spatial use of soil water is of special importance in miscd-cropping systems and in agroforest5
(adaptive/applied research).
IrrigaCon systems. Irrigated systemshave accounted for many of the increases in food productivity over
the last 30 years. While there is still scope for increased areas to come under irrigation (there are often
economic constraints), much of the irrigation water is currently being used only al lo-20% efficiency,
whereas some 80% efficiency could be obtained with sprinkler and drip irrigation. Increasing the
efficiency of use of irrigation water by methods of delivery and better scheduling is obviously a high
priori@ (applied/adaptive research). There is also scope for studies defining the periods of plant growth
where withholding of water is critical (or not).
Catchmcnt considerations. The catchment of surface waler in a landscape (for irrigation or human use)
will be largely governed by runoff patterns, and this needs to be monitored with different cropping/landuse systems, together with modelling of the consequencesof different land uses. Eventually, however,
decisions on overall land-use plxming are at a communily or administration level, not at the individual
farm level. Nevertheless,runoff is inestricably bound up with cropping practices on individual farms, and
the poorer practices also lead lo erosion.
There is an important need for a definition of aquifers and their behaviour in relation to farming/land-use
systems. A definition of aquifer quality and abundanceis essential in forward planning for irrigation and
its sustainability. Tree clearing in some areas has resulted in changes to underground waterflow, with
consequent development of dryland salinity over large areas. This calls for administrative action to
minimize tree clearing and for social studies lo define alternative sourcesof income from the land.
Erosion. Water erosion accounls for extreme lossesof productive land each year. Desertification, closely
associated with wind erosion, is about 200,000 km2 per year. Both types of erosion are symptomatic of
poor and unsustainable land management practices. the start of the downward spiral.
As well as having severe on-farm effects. water erosion involves lowcrcd water stongc of soil, incrcascd
runoff, and increased siltation of dams. Although there is a need for basic study on soil characteristics
leading to high erosivity, the most urgent need is to study soil loss (and water runoIl) as a function of plant
growth (affected by many faclors) and cover (spacing) during a season, management (e.g., tillage), and
soil permeability (affected by organic mailer) in different farming systems- a multifactor adaptive research
approach. In the rehabilitation of eroded soils, the first priority is lo replace some of the lost nutrients. 11
is here that lhe optimization of nitrogen fisalion by appropriately selected legumes (see above) is an
important strategy. Perennial legumes, such as trees (and nitrogen-fising nonlegumes such as Cnsuarir~~)
have an important role lo play in the conlrol of both waler and wind erosion, which is exacerbated by
overstocking.
Soil organic matter. The management of soil organic matter is also a top priority in sustainable
agriculture. Decline in soil fertility is invariably associatedwith a decline in soil organic matter, which
51
correlates with a loss of soil structure, lowered water inf;.ftration, increasing soil compactibility, soil
crusting, increasing erodibility and leaching, a decreasein the nutrient store, lower detosification effects,
and a poorer environment for fauna1activity.
A good number of studies have been carried out on the elfects of crop residues on soil organic matter and
the supplies of nitrogen and phosphorus to the soil, but such research tends to bc site-specific and short
term, whereas soil organic-matter changestend to be long term. There are now relatively good but simple
models describing organic-matter changes over time under a range of conditions. The potential of these
models is vety great for predicting the effects of different rotations, lillage methods, and the timing of
residue additions on nitrogen release, and they need to be tested on tropical/subtropical systems,
incorporating the effects of trees and of annuals where appropriale.
Soil biology. Although the effects of soil fauna, e.g. earthworms and sometimes termites, on soil physical
factors are well documented, there has been relatively little study on their management, except for the
recognition that their activity is closely related to soil organic matter. The selection of appropriate soil
fauna for introduction and management is al present in the strategic research phase, but its potential
importance should not be overlooked.
One of the most important missing links in our knowledge of soil fertility is the eslenl of productivity loss
due to unsuspectedsoil pests/diseases.These are likely lo be much more common than was suspected,and
may frequently be of the order of 30%.
Soil toxicities. These include salinity, high acidity, pollution by pesticides, and mining effluent (heavy
metals). In many cases‘tosic’ soils are the result of. or their estent is increased by, poor management.
Deforestation in catchmenl areas with a consequent change in waler balance has affected groundwater
flows and caused dryland salinity, often remote from the deforested area. Estrcme soil acidity can affect
the productivity of many agricultural soils in the pcrhumid lropics. This situation is esacerbated by
clearing and fertilization, and by the associatedleaching of cations and the loss of organic matter.
Genotypic selection for salinity tolerance and for tolerance to acidity or associated aiuminium or
manganese tosicib has been achieved with a number of plant species, and it is possible that genetic
engineering has a role to play in developing such genotypes in other species. The genetic approach is
likely to be a much a more acceptablesolution to acid soil problems than the costly application of lime.
An associated problem of acid soils is the unavailability of phosphate due to phosphate adsorption, a
problem that has largely defied solution by a!1but soil amendments.
Although there is a role for strategic/applied research in the amelioration oYprevention of tosic soils, e.g.
in defining salt movement as a function of water and salt flow in soil and of plant transpiration, there is an
important role for adaptive research because of the site-specificity involved. Site amelioration and its
consequencesfor crop sequencesand long-term changescalls for adaptive research.
Annex IV
Characteristics of the target zones
The desert fringe. The desert fringe has a mean annual rainfall of 100-400 mm, and the length of the
growing period is 1-75 days. The zone encompassesarid regions, which are cool to hot. Precipitation is
vety low and highly variable in spaceand time. Upland soils are predominantly shallow, sandy or gravelly,
\vith active clays which are often easily dispersed (sodic). Esamples of the desert fringe can be found in
the northern Sahel and in western Asia.
52
The major crops of the fringe are sorghum, millet, and barley. The farming systems are animal-based and
often nomadic.
The nonacid savannas. These areas have a mean annual rainfall of 400 - 600 mm. The length of the
growing period is 75-120 days. They have a relatively short rainy seasoncharacterized by high temporal
and spatial variability of precipitation, albeit not as high as in the desert fringe. Whilst most of the soils
are sandy or gravelly and shallow, the zone also includes large areas of Vettisols - swelling clay soils
which are potentially productive but difftcult to manage. Examples can be found in the southern Sahel
and in peninsular India.
The major crops in nonacid savannasare sorghum and millet. The famiing systemsare animal-based with
shifting cultivation.
The acid savannas. These areas have a mean annual rainfall of 600 - 1800 mm. The length of the
growing period is 120-180 days. This zone is characterized by a single intense rainy season, when the
soil is severely leached, and therefore has a low inherent fertility. The Cerrados area of Brazil is one
example.
The major crops are maize, sorghum, and upland rice. The farming systems are in transition from
traditional shifting cultivation to continuous improved pasture, or involve cropping with fertilizers and
other inputs in the humid forests.
The humid forests. The mean annual rainfall is >1500mm. The length of the growing period is >180
days. The drier parts of this region are characterized by a bimodal rainfall pattern, and the wetter parts by
a single prolonged wet season. The soiIs are mostly of low inherent fertility with low-activity clays. Those
of the drier parts are very easily,eroded. Examples can be found in the West African coastal region, the
Brazilian shield, and the Zaire basin.
The major crops are cassava,maize, and perennial tree crops. The farming systems are tree-basedshifting
cultivation.
The wetlands. These are regions which are flooded for at least part of the year. They can occur in any
climate. They include many small and large river deltas, tidal and other swamps, floodplains, inland
streams, and river valleys. The soils are mostly inherently fertile, nutrients being washed into them rather
than out of them: More than half of the irrigated areas in the world are used for flooded rice production,
and occur in natural or artificially created wetlands. Example of wetlands occur in the floodplains and
deltas of the Ganges,Brahmaputra, and the Yellow rivers.
The major crop in these regions is rice, with produclion based on continuous cultivation with fertilizers
and other inputs.
The stecplands. These are hilly and mountainous regions where the dominant slope esceeds 1%. The
characteristics of the soils and the climate differ widely, but the slopes result in a common problem of
water erosion. Esamples of such steeplands can be found in the Himalayan foothills, the Andean
Altiplano, and the hill arcas of northern Thailand.
The major crops in the steepland regions are maize, millet, root crops, and tuber crops. Farming systems
employ mised pasture and tree-crops with minimal inputs.
Annex V
SWNM problems of the target zones
SWNM problems of the desert fringe. Farming systemsin the more arid areas have been traditionall:,
based on nomadic herding. This is an appropriate responselo the space and time variability of the rains.
Unsustainability arises from resource degradation, due to the low carving capacity of the land and
increasing numbers of people and animals. In favourable periods, the number of animals increases, in a
droughl period all vegetation is rapidly eaten and the soils are exposed to wind, and when rain does fall lo
water erosion.
Nomadic pastoralism may be complemented by traditional rainfed agricultural production. Such
production is at high risk becauseof the uncertain rainfall. When the soils are cultivated, Ihe soil structure
deteriorates rapidly, and the normally low levels of organic matter in the soil are further depleted. The nel
result is that the soils tend to form surface crusts which further impede entry of rain into the soil.
There are many esamples of the response of farmers to these problems by water harvesting and waler
spreading, in which water running into gullies is diverted onto cultivated fields. These methods enable
some yields to be obtained, but they are almost always low or very low. Where waler is adequate, it has
been shown that responsesto fertilizers are common (Pieri, 1992). However, the use of fertilizers is rarely
economical. It has been difficult to establish more productive animal-based systemsunless water supplies
can be improved, and better systems of herd management to avoid overgrazing are introduced. Veliver
grass has been shown to be remarkably resistant to drought, and veq effective in reducing erosion. lt IS
largely unpalatable, so it remains as a soil cover even during droughts, but its unpalatability makes it
unpopular with some pastoraiists.
SWNM problems of the nonacid savannas. Population density in this zone is often relatively high.
Consequently severe degradation occurs on account of drought recurrence, overgrazing, overcultivation,
and deforestation (for fuelwood). In spite of the improvements which have been made in the plant type
and yield potential of sorghum and millet, yields in Sudan and Niger have fallen consistently from
1960/65 to 1992 (Table Al.l) - even during the recent successionof favourable seasons. ProducGon has
been increased by cultivating larger areas, including much marginal land, and by more frequent
cultivation of grazing land.
The deterioration of Iand in this zone has been referred to as desertilication, or in Africa as SaheiizaGon.
The process is associatedwith soil dcterjoration due to a loss of organic matter, erosion, crust formation,
and structural decline, and sometimes salinity. Together they may be more significant than postulated
changes in rainfall. While farmers are aware of the need to return organic material lo the soil, it is diflicult
to find material to use against the competing demands for fuel, animal fodder, and bedding and roofing
material. -Fertilizers can increase produclion from theseareas for a decade or more, but they cannot do so
indefinitely (Figure A5.1).
The erratic character of the rainfall is intensified by the elTe& of overgrazing and cuhivation. which
damage the natural vegclation and promote the formation of impermcablc crusts on the soil surface
(Albergel, 1987). Sustainabili~>~depends on the availability both of animal manures, or an alternative
source of organic material. and of ferlilizers. Under present conditions, sources of organic material are
becoming increasingly difficult lo find, aud fertilizers are not economically available. In spilt of the
resilience of theseareas (Rozanov, 199-l), they are OR a downward spiral of degradation. The deterioration
is most pronounced on light-testured soils, which are the most common.
Areas covered by Vertisols present their own special probbus. While these soils have a high &aterretention capacity, they are almost always mo hard or too sticky to be tilled. Management of these soils is
particularly diflicult when only human or animal power is available (Steiner er al., 1988). Where these
soils have high contents of sodium, they are liable to become severely compacted under continuous
cropping, and the soil may become barren, as has happened in northern Cameroon. However, many
Vertisols can be highly productive when they are put under proper management, as has been demonstrated
at ICRJSAT and in IBSRAM’s Vertisol network (IBSRAM, ! 989a,b).
Figure AL 1 Elect of fertilizer and manure on sorghum at Saria, Burkina Faso, 1960-l 980. (Pieri, 1992)
SWNM probkms of the acid savannas. In savanna areas, where rainfall is higher and more consistent,
the problem of water management is less serious than the problem of soil acidity. The soils have low
organic-matter and nutrient levels, which are further reduced by cultivation. Tillage of these soils,
especially when mechanized methods are used (Lal, 1991; Steiner ef al., 1988), can also lead lo surface
crusting, creating water-avaiiability problems.
In Latin America theseareasare often usedfor pastures,but they need lime and fertilizers if they are to be
productive (Sanchez and Salinas, 1981; IBSRAM, 1987a,c.) The productivity could be greatly enhanced if
suitable pasture legumes could be identified. Under cultivation, organic-matter maintenance is the most
critical faclor, as by complesing toxic aluminium it ameliorates the acidity problem as well as modifying
soil structyre and contributing to the nutritional status of the soil. It should be possible to identify
sustainable alternate pasture-crop or tree-crop systemsfor these areas, but to date there has been limited
success;most tree and pasture legumes are not adapted to the high acidity and low phosphate status of acid
savannas. When a tolerant specieshas been introduced, serious pest problems have arisen.
SWNM problems of the humid forest regions. The major causesof unsustainability in this zone are low
inherent soil fertility, with the result that yields rapidly fall to near zero, and the high erosivity of the
rainfall, which means that unprotected soils are subject to severeerosion. Under forest cover, nutrients are
efflcientiy recycled, and the soil is fully protected. The most adapted land-use systems are those which
mimic the initial rainforest, conservative agroforestry and tree-based farming systems with perennial
crops, such as rubber, oil palm, and cocoa. A leguminous cover crop can complement the protection
afforded by the canopy of the perennial, and with good management it may be possible to grow annual
food crops under the canopy. Such systems are sustainable only when they are economically viable, a
condition strongly controlled by external markets. This severely limits the area which can be used in this
way.
Alley cropping and other agroforestry systems mimic the protection of the forest, but their management
demands and the advantages offered over traditional shifting-cultivation systems, even where these are
deteriorating, have not been particularly attractive lo small farmers.
If the vegetative cover of the soil in this zone is removed, heavy rainfall induces the collapse of the
structure of the surface soil. This process can be dramatically enhanced if inappropriate mechanized
methods of land clearing are used (IBSRAh4, 1987b). As a result, runoff and consequent erosion increase.
The failure to return organic matter to the soil as forest litter leads to a sharp decline in biological activity
in the soil, and as a result the aggregation of the soil is lost and it becomescompacted. Under cultivation,
nutrients are removed in harvested products - and moreover they are leached becausethey are no longer
intercepted by the tree roots. This leads not only to nutrient deficiency, but also to acidification. Hence
cultivation of these soils is inherently unsustainable. Long-term experiments at IITA and in Ghana
confirm the rapid loss of fertility and the need to replenish nutrients and correct acidity. They have also
shown that systems without protection of the soil with a mulch or cover crop are unsustainable, even if
fertilizers and lime are used. Systems based on no-tillage and residue mulches allow a satisfactory soil
conservation level, but have not been widely adoptedbecauseof the difftculties of weed control without the
use of herbicides.
The traditional system of shifting cultivation in the humid zone was successful as long as there was
sufftcient land for farmers to leave the soil to rest under naturally regenerating forest for periods in excess
of a decade (Robison and McKean, 1992). As demographic pressure has increased and more and more
people have been forced to seek land in the forest areas, traditional systems have been replaced by crude.
slash-and-burn, in which the cultivation period is prolonged and the forest regeneration is endangered and
is inadequate to maintain fertility. The net result is deforestation with its various undesirable consequences.
Combinations of tree crops with arable cropping systems, and rotations of forest plantations with arable
production can be sujtainable if the efficiency of the tree crop in recycling nutrients and controlling
acidity is maintained. Productivity may be retained by careful management of nutrient levels, including
those of trace elements, and acidity can be controlled with fertilizers and lime; but it has yet to be
demonstrated that such systemsare economically sustainable. After reviewing the estensive literature on
shifting cultivation published since 1960, Robison and McKean (1992) concluded that “the problem is
worse today in degree and scale, and much of the problem lies with social aspects. Farmers’ perceptions
and decisions, economic trends, and government policy all effect the problem, and will have to be
reconciled in order for the problem to significantly, reverseoverall trends of degradation”.
SWNM problems of the wetlands The rice-based farming systemsof the wetlands of Asia are probably
the longest sustained production systemsthat exist. In parts of China, rice appears to have beeu grown
continuously for seven thousand years, and the main pillars on which such sustainability rests are
replenishment of nutrients in deposited sediments and from high nitrogen fisation, no erosion from
bunded fields, no acidification, relatively low weed problems, high phosphate avaiiability, and no nitrate
pollution of ground waters. These wetland areashave also been the centre of major successesof the green
revolution. Rice yields have been increasing for the past twenty-five years and continue to increase.
National average yields in China and Indonesia now exceed 5 t ha-r, and the concern about sustainability
is not, as it is elsewhere, about raising very low yield levels, but of maintaining and increasing high levels.
Long-term experiments at IRRI have shown a disconcerting downward trend for more than two decades,
and long-term rice-wheat systems in India and Nepal also reveal a downward trend. Rice yields in
Pakistan have stagnated for some time. Scientists at IRRl and CIAT have drawn attention to the serious
problems arising in the Philippines and Colombia becauseof stagnating rice yields (Cassmau and Pingali,
1993; Cuevas-Perezand Fischer, 1993).
Economic factors are one cause, as the responsesto inputs are falling as yields increase, so that against a
falling world rice price the system becomeseconomically unsustainable. Problems in the maintenance of
the water-supply systemsare another. Where rainfall is supplementedby irrigation, as it is in most of the
more productive rice areas, there are serious problems of waterlogging and salinization. In areas which are
naturally flooded, deteriorating conditions in the catchment areas, leading to greater depth of floods and
more frequent and persistent submergenceof the crop, are another cause.
Longer-term sources of unsustainability are associated with climate change, itself promoted by the
emission of methane from rice paddies. Most important will be the effects of any rise in sea level, which is
likely to have serious consequencesfor the cultivation of coastal wetlands such as those of the Gulf of
Bengal, the Mekong Delta, and the Guyanas. These effects will further aggravate the problems which are
56
already arising from human activities, such as embanking rivers to channel flood flows directly to the sea,
thus depriving basin areasof the sediments which formerly offset land subsidence.
Although the use of organic manures for flooded rice production has been widely advocated, their use is
declining, most dramatically in China. The major reason is the increasing value of land and labour, and
the decreasing cost and increasing availability of inorganic fertilizers. It should also be taken into account
that the advantages to be obtained from increased organic-matter levels are much less in flooded soils,
where it is necessary to disaggregate the soil by puddling to enable it to retain water, and where the
aggregating effects of the soil fauna are undesirable. The addition of organic materials is also undesirable
because.of the formation of phytotoxins in the anaerobic decomposition process, and the production of
methane, a much more active greenhousegas than carbon dioside.
Crop intensification in the wetlands has resulted in an increased prevalence of pests, including those
responsible for the propagation of vector-borne human diseasessuch as bilharzia, trypanosomiasis, and
onchocerciasis (IRRJ, 1989).
Most attempts to utilize the peaty and acid-sulphate soils of the wetlands have been unsuccessful. The
peats suffer from severenutritional problems which are difficult to manage. and the rapid osidation of the
iron pyrites of the acid-sulfate soils lead to the presence of free sulphuric acid in the soil and its
consequentsterility.
SWNM problems of the steeplands. The major causeof unsustainability in the steeplands is the water
runoff and consequenterosion which occurs whenever steepslopes are cultivated. Traditional methods for
sustaining farming in these areas include the construction of terraces, and the maintenance of a cover on
the soil of a perennial pasture or an organic mulch of materials taken from the forests growing on
adjacent, and usually more steeply sloping, parts of the mountain or hillside. These traditional methods
have broken down as population has increased and forests and pastures have been destroyed by
overexploitation. The pressures on the steeplands have often been temporarily relieved by outward
migration to the lowlands; but without continuing economic development in the adjacent lowlands, such
migration may create as many problems as are solved.
Erosion in these areas is not necessarily man-induced. It often involves mass movement of soils and
landslides as well as loss of topsoil, and the results are often easily observable. Steeplands are typically
zones where the effects of unsustainability must be viewed on a variety of space scales, from field plots to
subcontinental watersheds Erosion in the Himalayas may be responsible for the siltation of reservoirs and
canal systems in the northern plains of India, and also the source of sediments which are the basis of
sustainability in farming systemsi,n Bangladesh. While the effects of unsustainability are most pronounced
and easily observed in mountain areas such as the Himalayas and Andes and the highlands of East and
Central Africa, the problems are common to most areaswhere slopesexceed 13% (IBSUM, 1988.)
SWNM problems of irrigated systems. Traditional smallholder irrigation based on simple technology
has long been practiced in the rice areas of Asia, and in the dry areas of north and northcast Africa,
western Asia, and Latin America. The rapid espansion of irrigation has been a major factor in the
successesof the past 25 years in increasing production not only of f&xl crops but of cash crops, such as
cotton, on which much of Third World development has depended. Any threat to the sustainability of
irrigation systems is a serious threat to development. Thus it is a matter of some concern that a serious
threat does in fact exist. The threat arises from waterlogging and salinization in irrigated command areas,
and from erosion in the catchment areas of reservoirs leading to siltation, and reduction of the capacity of
storages,and choking of the distribution systems.
Problems in many traditional as well as modern irrigation systemsarise from inadequate drainage of the
irrigated area. Concentration of water in an inadequately drained area leads to waterlogging or a rising
water table. If the underlying water table contains saline water, as it often does in arid and semiarid areas,
the soil will be salinized and productivity will be severely reduced. More than half of the present irrigated
areas have been affected by salinization, and every year several million hectaresare abandoned becauseof
salinization (Ahmad, 1991). A recent study in India has shown the economic importance of salinization
problems to small farmers in different areas within a major irrigation system (Joshi and Jha, 1991), even
when the salinity problem is not particularly severeand the land is unlikely to be abandoned.
57
The problems of reservoir sedimentation are probably as serious as those of salinization if sustainability is
considered in terms of decades. Most irrigation systemsare designed on the basis of a life of a century or
more, the limitation being the rate at which the storage capacity is reduced by sedimentation. In fact most
of the major storage systemsconstructed in developing countries in the recent past are now known to be
suffering from siltation rates which will reduce their capacity far more rapidly than estimated when they
were constructed (White, 1990; Shahin, 1993). For example the Kashm el-Girba reservoir in the Sudan
will have lost 55% of its original capacity in 25 years, and the High Aswan Dam reservoir is now expected
to have a life which will only be 50% of the design expectancy. A survey of reservoirs in major irrigation
systems in India has produced similarly disturbing data (Table AI.2). In the Philippines, the loss of
‘storage capacity in the major reservoirs from which the principal rice-producing areas are irrigated has
meant that water is not always available to the rice farmers during the growing season. Future prospects
for increased production to meet demand are therefore facing serious difficulties (Masicat et al., 1990).
The source of the sedimentation problem is, of course, the increased intensity of cultivation and
deforestation in the catchment areas, resulting in erosion rates above those assumedat the time the dams
were designed. The situation might be improved by restrictions on slash-and-bum agriculture in the
catchment areas, although where such regulations have been introduced they have been ineffective unless
an alternative source of livelihood is offered to the cultivators.
As with soil management, much is known about how to improve water management. Great improvements
in the efftciency of water use are possible, and the need to ensure adequatedrainage at the time irrigation
systemsare constructed has been constantly emphasized by soil scientists and agronomists. The need to
ensure proper erosion control and prevent deforestation in the catchments of major reservoirs has also
been stressed. Again, the problem has been to find economically viable and socially acceptable ways to
include these measuresin the planning and development of irrigation schemes. In a report on the need for
research on irrigation to improve food production, Pereira ef al. (1979) noted that in the vast irrigated
areas of the Gangetic plain, the Indus basin, and the valleys of the Nile, Tigris and Euphrates, crop
production was less than a quarter of the potential createdby the amounts of water available.
While the problems of large irrigation schemes are now well known, new schemes are still being
undertaken with inadequate data, particularly where microdams are being constructed, as in the semiarid
regions of northeast Brazil, northern Mesico, and the Sahel. The lack of appropriate complementary
inputs, poor water control, the absence of double cropping, and inappropriate agronomic practices
commonly result in production that is scarcely superior to that obtained from rainfed agriculture. If the
external costs of loss of grazing and other land, fishing opportunities, and of moving people are also
included, it often becomesdifficult to justify the investment in irrigation (Matlon, 1987).
Unsustainability in many irrigation systemsstems from the fact that for the last four decadesinternational
assistance for the development of irrigation resources has concentrated on provision for capital works
designed by hydraulic engineers. Too little attention has been given to the warnings of soil scientists and
agronomists, and often none to the problems seen by the farmers who will be using the water provided,
and the effects of irrigation developments on the role of women in farm and household management.
Although these issuesare receiving increasing attention (FAO, 1987b; Samad et al., 1992), much remains
to be done.
Annex VI
Responsesto the questionnaire
Synopsis of survey results. In an effort to gain a better appreciation of the perceptions of organizations
and individuals working on SWNM problems in developing nations, a questionnaire, was. distributed
widely by the consulting team. Four open-endedrequestswere asked:
58
.
.
identify
identify
identify
identify
l
.
.
5 major problems in SW;
5 most crucial knowledge gaps in SWNM;
5 priority researchareas;and
neededapproachesto addressSWNM problems.
Thirty-three organizations responded.
Type of organization
1. NARS
2. Developed-country organizations
3. CGIAR institutions
4. Non-CGIAR (ICIMOD, IFDC)
5. Regional bodies (TSBF)
Percent
33
Number
11
11
8
2
1
’
33
24
6
3
The survey results are depicted as histograms in the text (Figures I11.2. and 111.3.)and in Figures AVI. 1
and AVI.2. Each respondent described problems in their own words, many listing less than five requested
responses.’The individual responseswere then listed and grouped according to logical categories by the
responses.
20
Legend
Translating SWNM into practical technologies
Integration of socioeconomic/BiophysicaJ ~~pc.cts
Nutrient management techniques
Minimum data sets/GIS/AEZ and SWNM
Improved understanding of soil nutrients
Improved research methods
So3 organic matter
Better rcchnicnl knowlcdgc for suslainablc SWNM
Better fertilizer use
Managing acid soils
Managing soil-water across seasons
Berrcr water management (inc. storngc)
Pollution and agriculture
Water-nunient interaction in crops
Gmsslands management
N=129
FigureAVI. I Perceptionsof major gaps in SWNM research.
In brief, the perceptions for each category can be summarized as:
l
l
l
l
Major problems.
On the technical side, nutrient recycIing&ming, soil erosion/degradation, and
water management were thought to be important. On the socioeconomic side, respondents saw
prices/policy/markets along with faulty researchsystemsas the main probIems.
Major gaps. The two most salient major research gaps identified were ‘translating SWNM into
practical technoiogies’ and ‘integrating socioeconomicand biophysical aspects’.
Major research priorities.
OvenvheImingIy, the perception is that more adaptive on-farm research is needed.
Achieving results. The primary suggestions called for interdisciplinary research, strengthening
NAFLScapacity. better coordination, and long-term esperiments.
Legend
-- - 0
--I
Interdisciplinary research
LAR6.S anb NARS
Be&linkage:
Stronger links: Scientists/farmers
8 Long-tctm experiments/Pilot projects
fZZl EducWSupport policy makers
CI International network
i I3 Bcttcr scicnce/Expedmcnts!Labs
Building on farmer knowledge
Disseminntc approprintc methods
Link cnvironmcnt/Agriculture centers
Figure AVI.2 Perceptions of linkages required to supportSWNM research.
Annex VII
Comparative advantages in basic, strategic, applied, and adaptive research
If consortia on land management are to operate effectively, there needs to be a clear accep:ancc of roles,
related to the comparative advantagesof each participant. These differ considerably according to whether
the research is basic, strategic, applied, or adaptive.
Basic research. In basic research wc would not espect the international organizations to bc heavily
involved. other than the International Council of Scientific Unions (ICSU). In national terms most of the
basic research will be conducted in universities and specialist research institutes. An example of an area
where close linkage between the international centres and basic researchorganizations is highly desirable
is in work on global climate change and the way in which changes in land use are effecting the releaseof
carbon dioxide and other greenhousegases. ICSU has estabfishedthe International Geosphere-Biosphere
Programme (IGBP), and within that a ‘core project’ on Global Change and Terrestrial Ecosystems
(GCTE). There would seemto be a strong case for strengthening the linkages between the GCTE project
and the CG and other centres involved with SWNM research. A linkage between IRRI and the GCTE
project already exists, relating to the evolution of methane from rice paddies.
Strategicresearch. Strategic research is the great strength of the CGIAR centres. We would expect the
CG centres to maintain a leadership role in strategic research,emphasizing even more strongly than in the
past the linkages between crop improvement and natural-resource management, and including in this
survey socioecondmic and policy studies related to natural resourceuse. The CG centres already have very
strong linkages with many other strategic research organizations in developed and developing countries,
60
and we would expect that these would continue, and that they would be further strengthened by
involvement in SWNM research.
One example is in the development of an international data base on agricultural environments, in which
several of the CG centres have worked closely with FAO and other organizations; another example is in
the conduct and managementof long-term experiments, intended to be continued for decadesrather than
years.
The latter issue merits further consideration. While there has been much recent interest in the indicators
of sustainability, there is no way in which any certainty can be given to discussions of the sustainability of
a particular land management system unless there is an experiment which measures the changes in the
indicators over time. As discussed in Section IV, particularly important - but difficult and espensive to
manage - are such eqerimcnts conducted on a catchment basis. Relatively few countries have the
resourcesto maintain such esperiments.
Nevertheless several such experiments ‘need to be conducted as a reference for related sustainability
studies, and should be managed as an international responsibility, with other trials on a plot rather than a
catchment basis conductedby the NARS in a wider range of environments and directed to answering more
specific questions. The NARS may often be supported by international projects in the conduct of such
trials, as in IBSRAh4 networks, and in the trials which are being developed as part of the ‘Alternatives to
Slash-and-Burn’ project being developed and managed by ICRAF. Both IBSIUM and ICRAF have
established strong linkages between the organizations concerned with strategic research and those
concerned with applied and adaptive researchactivities.
Several of the national programmes are also conducting important strategic research on aspectsof SWNM,
and are normally willing to share their results with others. To mention just one example, the Indian
Salinity Research Institute is conducting vitally important work on the salinization of soils and their
recovery for agricultural use.
Applied research. The distinction between strategic and applied research in relation to SWNM is very
blurred. The TAc’s definitions of the research categories (Figure 11.2)distinguishes applied and strategic
researchon the basis that the purpose of applied research is to create new technology, whereas the purpose
of strategic research is to solve specific research problems. Thus most of the CG centres are likely to be
involved in both strategic and applied research, while national programmes may be more concerned with
applied and adaptive research.
Adaptive research. The TAC defines adaptive researchas the adjustment of research to meet the specific
needs of a particular environment. The great diversity of land systems,and of the social, economic, and
political conditions in which land is managed requires that responsibility for adaptive research must be
accepted by national governments. Support for them is needed from various international endeavours.
The support may best be arranged by networking between the various organizations involved on the basis
of commonality of problems, enabling the experience of the different national programmes to be cffcctively
shared, and avoiding the potential for considerable overlap in researchactivities.
There would seem to be a significant comparative advantage for national programmes in conducting landuse planning and development activities within their boundaries, but international organizations are likely
to have a considerable comparative advantage in the organization of consortia to share experience and to
link strategic and applied research. Such work may be greatly facilitated by giving greater emphasis to
site characterization, and by developing a better system for information eschange. The linkage between
strategic, applied, and adaptive research may be a considerably strengthened if all concerned work
together in a consortium which is directed to the solution of one of the top-priority problems.
Annex VIII
About the authors
Dennis Greenland is a soil chemist, and currently visiting professor at the Department of Soil Science of
the University of Reading, UK. He has p&ously held appointments at the Universities of Ghana and
Adelaide, and was director of research at IITA, Nigeria, deputy director general (research) at IRF3
(Philippines), and director of scientific servicesof CAB International, UK.
Glynn Bowen is a soil biologist. He is honorary senior researchfellow a! the CSIRO Division of Soils in
.Adelaide, Australia. He has worked in Asia, Africa, and Latin America in training and research
programmes related to nitrogen fisation and plant nutrition. From 1986-1991, he was head of the Soil
Fertility Section, Joint FAO/IA?ZA Division, Vienna, Austria.
Hari Eswaran is a soil scientist specialized in soil survey, classification, and conservation. He is
currently national leader of World Soil Resourcesat the Soil Conservation Service, U.S. Department of
Agriculture, where one of the projects he manages deals with enhancing the quality of soil resource
information for sustainable agriculture in developing countries. He has worked in 75 countries. He was
previously at the University of Ghent, Belgium, and at Cornell University, Ithaca, New York.
Robert E. Rhoades is an anthropologist with over two decadesof experience in agricultural development
projects. He spent 12 years at the International Potato Centre (CIP) in Lima, Peru, and is the founder of
UPWARD (users Perspective with Agricultural Research and Development). Presently he is head of the
Department of Anthropology, University of Georgia, USA.
Christian Valcntin is a soil physicist employed by ORSTOM, France, and working in Niger. His main
field of e?;pertiselies in small watershed management and related crust formation in the St&no-Sahel
areas. He presently leads a research unit in ORSTOM on the dynamics and rehabilitation of water
resourcesin fragile and highly populated tropical ecosystems.
62
.
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Abbreviations and Acronyms List
ACIAR
AVRDC
BNF
CAB1
CGIAR
CIMMYT
CIP
CRSP
DANIDA
FAO
FSR
GCTE
GIS
GLASOD
IAEA
IARCS
IBSRAM
ICARDA
ICIMOD
ICR4F
ICRISAT
ICSU
IFDC
IFPRI
IGBP
IIMI
IITA
ILCA
IRRI
ISNAR
ISRIC
ISSS/CIP
IUCN
NARS
NGO
ORSTOM
SWNM
TAC
TSBF
UNCED
UNEP
UNESCO
USAID
WHO
WMO
Australian Centre for International Agricultural Research
Agroecological zones
Aisan Vegetable Researchand Development Cenlre
Biological nitrogen fixation
CAB Intemationai
Consultative Group for International Agricultural Research
Centro International de Majoramiento de Maiz y Trigo
Centro Intemacional de la Papa
Collaborative researchsupport project
Danish International Development Agency
Food and Agriculture Organization of the United Nations
Farming systemsresearch
GIobaI Change and Terrestrial Ecosystems
Geographical information systems
Global assessmentof soil degradation
International Atomic Energy Agency
International agricultural researchcentres
International Board for Soil Researchand Management
International Centre for Agricultural Researchin the Dry Areas
International Centre for Integrated Mountain Development
International Council for Researchin Agroforestry
International Crop ResearchInstitute for the Semi-Arid Tropics
International Council of Scientific Unions
International Fertilizer Development Cenlre
International Food Policy ResearchInstitute
International Geosphere-BiosphereProgramme
International Irrigation Management Institute
International Institute for Tropical Agriculture
International Livestock Centre for Africa
International Rice ResearchInstitute
International Service for National Agricultural Research
International Soil Referenceand Information Centre
International Society of Soil ScienceKommiltee on Interuational Programs
World Conservation Union
National agricultural researchsystems
Nongovernmental organization
Natural resourcemanagementresearch
Institut francais de recherchescientifique pour le developpment en cooperation
Soil, water, and nutrient management
Technical Advisory Committee to the CGIAR
Tropical Soil Biology and Fertility programme
United Nations Conferenceon Environment and Development
United Nations Environment Programme
United Nations Educational, Scientific and Cultural Organization
United StatesAgency for International Development
World Health Organization
World Meteorological Organization
World ResourcesInstitute
71